I think Mick loses his steam rather quickly because of what has happened over the years of the game, though it is a little wrong to get the hopes up of the left over players.
You have to think about the way we've lashed out at him over the years everything from calling him names/cursing him.. releasing server files that weren't supposed to go public (this was probably a major downfall of the game - He mentioned when it first happened not to trust the servers because they were viruses. I think the knee jerk reaction was enough to tell it was going to effect it) and the fact that (unless I've missed something) he hasn't got anything back from us since perks were relevant.
So you have a guy that owns a game, that has somehow managed to stay around regardless of us abusing him and not really giving anything really back to him. Yeah your argument might be that there are players keeping the game alive and that's because of the whole server publication. I really don't believe V2 server would have been made public if V1.15 wouldn't of been leaked years ago. Not to mention some people keep servers open to try to make a quick buck off players that are willing to pay them for services (flatten land, "hearthstones", etc..)
Anyways updating or fixing the game only has a few outcomes and really the pros don't really outweigh the cons, so I figure that's why he decided not to, and hell I could be wrong and he's just silently working away at it every few days, but in reality if he's doing this for money, he probably won't release it, he'll host it himself and put someone (more then likely someone a lot of people can't stand) in charge. I figure now-a-days he has trust issues with most players just because of the amount of bull crap we've put him through.
PS: As far as the different versions, it was an attempt to make money/modernize the game. Part of me thinks he let Jon drag him too far off course to ever really accomplish it, each version pass V2 has tried something fancy regarding graphics and if he would of stuck it out with V2 in the past and did some major work on it, interface and all. He may have been in a better position today (again leaked 1.15 didn't help this case)