Sigh...
Not sure exactly why he left. Seems many people jump back into Atari for multiple reasons. Some for nostalgia, some for the uniqueness of it all, some not sure why.
Me, the Atari 8-bit computer was my first computer. I have some fond memories of times with dad, times playing games, times on BBS's. And those memories continue.
But I have noticed that some get a project in their head, and they go a good ways. But then when they make a game, and the feedback is few, they get deflated it seems. And after a while of thinking no one cares, fade away.
The problem with a hobby like this is, it takes a back burner to real life. You cannot expect time lines to be the same.
And projects well.. you start them, you have initial interest, interest might pop back up a year later, but ultimately projects are judged three ways in time in this hobby:
1) Not finished, but source code/work released for someone to follow.
2) Not finished, and all lost... a terrible loss.
3) Done (which is generally remembered by at least one fan fondly.)
I have found that many who leave this hobby tend to be those that worked on a project, and when it grew long in the tooth, and no on gave feedback, decided to move on in life.
Can't blame. But then again, I appreciate all that do things for the Atari platforms. Sorry I can't jump on or appreciate projects nearly as much as their creators, but it is appreciated. Even if it takes me a few months to get around to trying something.
And that is something you have to do with this crowd. Make something, then give it a few months. Then occationally remind people of improves, revisions, updates. That seems to be the real trick to this.
And you the user, if you start feeling burned out with Atari stuff, just take it easy for a while. Box it up, give it half a year. Maybe you're ready to move on, or just maybe you need a little break.