I think the big plus to such a large cast is that the story feels far more real, at least to me - I like seeing other guys in the story for example because at a college, there will be other guys around, etc. I hope we see some of the other guys at the college even pursuing our LIs to add to the realism with some competition for their affection. It's also good because of the "gossip" factor which adds angles to the dialogue since the characters do talk to each other in the background as Ocean has described previously - if you are romancing Bella, word gets around that you two are a couple and people react to that information based on their opinions of Bella & the MC (just as an example).
But at the same time, there is the potential downside of some LIs not being fleshed out very well until further into the game - we've got plenty of people on the board that are looking forward to Sasha. Myself and some others are looking forward to Amber (and heck if you aren't on Bella's path you don't even get to see Amber in a single render from Chapter 4.5).
So I know bigger casts can be tougher for the developer to manage, but overall I think it's a positive.