I hate to appeal to authority Crab, but really, if you weren't around and following 2008 you really won't get how astonishingly brutal it was. Both campaigns waged a bloody, difficult war, and the idea that the current situation is worse is just not at all believable (see the numerous people saying the same thing in this thread). Heck, many of Bernies primary voters on this very board have said they will happily support Clinton when she wins - that was unheard of in 2008.
Obama and Clinton basically split the party in two, and it was a huge concern of everyone that it wouldn't be possible to mend that breach. It took a huge amount of work from both sides. Bernies not getting near that level of acrimony - yes, he has a small, passionate base of support. So did Ron Paul.