This part at least I can understand. If you as the dev don't like what you're creating then it's doomed to failure. So continuing the previous version would likely have just lead to it being abandoned. So from that standpoint the rebuild is a good thing.However, the most important nuance is that the old version was not what Alexey wanted to create.
Not sure what lead to him creating content he didn't like in the first place, but from my modding experience I suspect maybe he let his fans lead him astray and develop in a direction he personally didn't like. I tried that as well and it just doesn't work.