I came to the wakfu beta with the feeling of playing something similar to fft or disgaea. So the step to building your own team or at least half of it with one account is a great step.
I have 4 accounts and like to reduce the number of running clients to two. Then I can finally use the the second screen for something else again
I can even arrange myself with abandoning the effort I did on the 2 accounts I might stop actively playing. Leveling alts to the same level is easy nowadays with x2 or x3 XP.
I think that the culture and community will not be changed much more than it was right from the beginning of the game. In the beta and in the first half year after wakfu leaving the beta stage (which it never really did, i know...) I played only one account. But many things were wasted time then. You had to wait 10 seconds until you had chopped a tree. About 7 seconds wasted. There was only one other person online in your guild for the dungeon you wanted to run, and your sever is Amara. About half an evening wasted. Just 2 examples.
Multiboxing was the way out of this. I know many people that started multiboxing very early on. Heroes are just a positive evolution of it.
Other people already played sidekicks for about a year. If those people started playing heroes, you would not see a difference.
I do like playing with other people. But wakfu's round based combat is not really supporting playing with other people. If you are only playing one character in a dungeon run, then you might have to wait 5 minutes until it's your turn again. I knew people that regularly fell asleep at dungeons Or missing their turn because they were doing something else in the waiting time.
The hero system will be a bless. If you wanted to strengthen the social aspect of the game, there would be other aspects that should be improved.
(all this rant is not directed at someone in special, but maybe the thread title...)