well the dev has to eat, it's great that they're charging real money to create a real tool! i hope it becomes a trend during this rpg maker generation, so that we can have a rich array of very powerful commercial development tools for rpg maker.
after all, in the previous rpg maker generations all 3d-like solutions were free, but none of them did 5% of what mz3d can do and didn't have the budget to keep continued support / updates etc