I mean, I could say the "gogogo" mentality is also a "diva dps" mentality, since they just care about dpsing as much and as fast as possible with no regards for others in the group no?
Either way, I'm sure that happens in some cases, but in most?
The problem with the "gogogo" mentality is that it almost always isn't just one or two pulls, more often than not it ends up becoming a full dungeon where the tank instead of pulling at his own rythm, instead has to spend the whole time running after and taunting mobs pulled by others, which depending on the classes involved can be very frustrating for the tank and potentially for the whole group (if it results in scattered mobs and/or deaths).
That's what generates the "you pull you tank" mentality, imho, tanks (who might be unexperienced or just not very good) having to consistently run after and taunt mobs others pulled is a lot more frustrating and gameplay-changing than a dps having to attack 4 targets "only" instead of 8, imho. It's not about "ego", it's about being "forced" to play in a fundamentally diferent way (rather than just slower than what you'd want). It's just rude.
I mean, I've been in both ends of the situation (being a newish or undergeared tank and people rushing me, or being a geared dps on a very slow group), and I understand slow pulling can also be frustrating, but at least personally I empathize a lot more with the tank. It's much less big of a deal to just dps fewer mobs in a slower fashion, and has a lot less impact on actual gameplay.
Also it's sort of WoW "dungeone etiquette" to simply let the tank do the pulling. It just makes everything easier for everyone, and more often than not results in a more positive experience for everyone involved.
There are some exceptions, of course, in cases where it's absolutely clear another group will not be dangerous and it's made with common sense (pull them to the tank, or use md/tot on tank). But generally, you should just ask if it would be possible to pull more, or state the group would survive bigger pulls just fine.