I’ve run stuff with a shotgun/hammer tank before. Just because it’s not popular doesn’t mean it’s not possible. It’s like saying that no-one uses blade as an endgame weapon. Very few people do, because there are other weapons which are easier to master and perform well with, but there are also those who have decided that they want to use a sword and ignore people who tell them to stop.
You can tank with any of the tank classes. By the time you’re encountering content that you need specialist builds for, there’s a good chance you’re going to already have access to it.
Tbh, I think some of the confusion could be mitigated by calling them “starter classes” (or something similar). People were confused by the use of the word “deck” in TSW, but just calling them classes puts a set of expectations on them which they may not be able to meet.
I don’t think that any of the classes perform particularly well in endgame except the healing ones (and even then, there’s better combos really). But it’s always going to be the case that trying to select a variety of weapon combinations so that everything is a primary once and a secondary once will yield a limited number of combos.
I don’t think that the game is trying to deceive anyone tbh. I think that it could have been done a lot better, and tried to explain more that you aren’t limited to your initial weapon choice, but it does help spread peoples’ experience out across a variety of weapons instead of everyone just going cookie cutter.