I think that one problem here is some players are looking at it from a higher level perspective of someone who is well geared and experienced while the rest of us are looking at this from the perspective of someone who is still learning.
Scoundrel, Musketeer, and Bard can tank up to around Shard 5 depending on their gearing and talents. Musketeer and Bard can both do DPS as well.
Paladin can heal.
Shaman, Ranger, and Runemage are pure DPS. (Shaman and Runemage might be able to do some support, but not enough unless you have a really good tank in an unsharded or low shard dungeon)
Warrior… is basically just a tank. Despite having a DPS option, the problem with Warrior DPS is that it isn’t feasible at lower levels. Yes, if you are high level and have the overlevel movement speed and such, it might not be an issue, but at lower levels, mobs can outrun you and outheal you. Maybe if you are really skilled and experienced already, you can deal with the outheal, but there are some mobs that do seem to heal a bit more often than some cooldowns allow for (particularly if there is a group (which some enemies are grouped))
And as Richleth said, a “good” warrior tank can do Lich King on a 15 shard. Problem is we are talking about unsharded (in other words, less experienced Warriors). I’ve had people leave dungeons because the tank couldn’t do a boss. One wipe and they are out. When the boss is constantly rotating, your party has to get closer to the Lich King or get very far away to give time to dodge or spin with the tank. This might not be an issue in higher shards where players are likely to be more or less familiar with the mechanics, but it is an issue with lower level, unsharded dungeons where players will quit if the tank is so much as level 10-15. (Because it is unfeasible for a level 10-15 tank to hold aggro against 3 level 30 [runemages] and those [runemages] get upset when the tank can’t take aggro away. (Replace [runemages] with really any level 30 DPS that can’t take hits). Also that there are only around 10 ‘good’ Warriors on the entire server kind of says a lot about it being a problem.
It breeds ill will and resentment, reduces the incentive to learn, and reduces the ability to learn. That is why making the warrior more viable for ‘not good’ Warriors is just as important. Of course, if Warrior gets too big of a buff, it will just swap Warrior around to being the preferred tank class, but letting them block ranged attacks with their shield would still help in PvE and PvP. (I also note that nobody is arguing that Warrior is useless in PvP).
Even if blocking ranged did double damage to the shield and did no aggro generation, it would still help Warriors. It would make things somewhat easier for less skilled warriors and for more experienced/skilled warriors, it would be a viable emergency measure without being too overpowered.
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I’ve done dungeons with a level 1 warrior tank (one of which ended up around level 6 over the course of two dungeons queues), but we had to teach them how to tank and they were willing to listen to us. I had to offtank as a bard so that the bosses/enemies would go after me instead of our dps and our dps had to lower their dps though. This was with a party of people I knew and we are very patient when it comes to someone willing to learn. Many groups are not like that. We had at least one person leave when they saw the level 1 tank was actually tanking as a level 1. And this was with ones that were willing to learn from others.
You have those warrior tanks that only listen to ‘oh my friend told me that this is what I should do’ or ‘this is what it said to do online’ (we’ll ignore the ones that completely refuse to listen to anyone) and tempers tend to flare up. I don’t even bother reporting some of the stuff that gets flung around since it is kind of understandable that it is just people seeing red from anger and frustration.
You also get the cases of tank willing to learn, but party unwilling to deal with teaching them. That usually ends with players leaving (sometimes after insulting the tank) and the run failing even if one or two players are willing to teach the newer player. If you are lucky, you might get a runemage that is so high in dps that they can just destroy any enemy that pops up short of bosses (and potentially even bosses) and is willing to near-solo the dungeon, but the tank doesn’t learn anything except that runemage does a lot of damage.
These factors just make Warriors a tank class that very few players want to play (the damage issue doesn’t necessarily help either) on top of many players not wanting to tank in the first place. By improving Warriors so that they are a bit easier to use for newer players, you encourage players to learn the class instead of skipping it or powerleveling it (without actually learning it).
Some players might be fine with only the ‘select few’ knowing how to do things, but I’m not that way. If I know something and someone is willing to learn, I’m willing to teach them as far as I am able. The problem is that in order to really teach, you need an environment where that is feasible. Right now, you may or may not get a group where it is feasible to teach a new Warrior player.
By making it so that it is easier for a Warrior to tank in a way that is easier for the party, you encourage new Warriors to learn the class instead of giving up (either due to frustration or due to being discouraged by others).
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Also, Pistolers are the worst on the airship and sometimes you can’t use the incline method to deal with them because they will leash. This is especially ‘fun’ if you 3 Pistolers and at least one healer. While a Paladin can soak the hits for the party if needed (a lot harder to hold aggro when you are moving the entire time as you cannot move while your movement hand is vertical (Quest 2) and moving when the controller is facing a weird direction can be somewhat confusing for some), the Warrior can only dodge. This can kill a player that is used to using the tank as a shield or that wasn’t able to see the shot (due to something blocking the visual).