That's how it works in most cases in the avn industry, basically. You can compare it with how movie or tv-shows industry work. Each new update is like a new season or the next part of the movie. It takes a lot of time and money to produce a new update. So you can pay each time when the new update releases, or wait until it's completely finished and pay only once. Tho, as I said, it may take a while. I understand that not everyone is ok with this, but I don't force anyone to play or pay. Everyone decides for themselves. Once the game is finished, it'll be released as a complete game here and on steam. For now, it is as it is.