Personally I miss the option for general talents, it feels like a strange omission. As Gromnir said, it's probably an issue of ability bloat. I also remember plenty of complains about Pillars 1's classes not feeling distinctive enough(though I never really felt that myself) so maybe the idea to tighten up each classes' unique strengths was a motivation. With multi classes(and to an extent subclasses), you have a lot of tools at your disposal to build in many different ways, which of course makes up for some of the loss.
My concern is that because there is no general talent pool any more, it won't feel all that great to pick a base class. As of right now, I don't see it. But it's also way too early to tell. I will say that I really hope picking a base class turns out to be just as enjoyable as a multiclass(or even a subclass for that matter), because it really is a shame if it turns out that being a "pure" class is just rendered boring and obsolete by everything else. There's something to be said about wanting a character who is dedicated to a single discipline, but still have variety in the way that is expressed, especially for roleplaying purposes.
With all that said, I think the custom titles for each combination of multiclass does help with that last point, because while mechanically you're playing two classes, from a character idea or roleplay perspective, it feels like its own unique thing. We shall just have to see how much diversity we see in build types mechanically as we continue tinkering however.