Now that the dust has settled, why are some people so brain dead that they unironically believe that getting investors into VTubing is a good thing?

You won't see the changes immediatelly, they always try to keep continuity going for a while. But bit by bit, things will be streamlined. You don't give someone 11 million for charity, you expect a hefty ROI. This year will be good, from next year you can expect that all the little edges and wrinkles on your favourite VShojo will be worked out to ensure she can hit a wider audience while the new generation will be vetted accordingly to ensure maximum marketability.