This game's meta has made it very clear that no single role's DPS is insignificant. Everyone should be trying to perform their hardest to add to the DPS pot in a group.

If you stacking STR then watch your HP, are you dipping below 50% 10 seconds into a pull?
Are you using proper cooldown together to get the most mileage? ( ie not stacking rampart and sentinel due to diminishing returns)
Are you aware of your party makeup? ( ie if you have all melee DPS what reason is there to pull large groups?)

If your aware of how much damage you are taking, using cooldowns properly, and pulling to suit the party makeup then there's almost no reason to not run at least 3 STR accessories on tank in the current meta. That being said, if your a fresh 60 rocking only Valerian gear then by all means throw on a couple extra, but even then you could easily only have to use 3 VIT accessories. the expert duties really don't need anymore than 16-17 k HP, and Alexander normal is the same. I run 5 STR pretty regularly, but I always do a small pull first, if the healer is incapable of keeping up then I throw 2 VIT accessories on and call it a day. If they do well then we continue with 5. It's a simple matter of tailoring yourself to fit the needs of your party, whether or not the group is capable of handling it is really immaterial. Arguing in DF with people that are close minded is just a significant waste of time. It is impossible to talk sense into the opinionated.