1.AAA companies with millions of dollars and many people on staff have done the same thing.
2.this is one to a couple people without a budget other than what their supporters give them. and it might not be their full time job.
3.because since 2005, people have been able to update games anytime they want. this is like early access on steam. support them now. it helps them develop it. you play later when it is done or farther in development.
hopefully you learned something. and correct others when they ask questions with obvious answers.