Anybody who liked Garfield as a kid has an object lesson in exactly what he was trying to avoid.
At the same time, I think the OP's point is that the "trying something else" never seems to have materialized.
At the same time, I think the OP's point is that the "trying something else" never seems to have materialized.
He made people happy for a decade (and longer with reruns and memories) and you've decided he's an asshole for not doing it for longer.
I think that's harsh - ultimately you're saying you want him to do work he isn't happy with and causes him stress for your entertainment.
If you think he knew for sure that he wouldn't do anything similar again yet said this then you'd be justified in saying that he'd mislead people (which wouldn't make him a hypocrite, rather an outright liar) but there's no evidence that that's the case. The guy worshipped cartoons and had worked for years to become then remain a cartoonist. As stressed as he'd been by it all I suspect he felt there was a chance he'd return to it at some point (and may still do, though that seems unlikely now).
But at the time he quit, like many people ending a long term, all consuming project which has left them financially secure, all he really knew was that he was going to take some time out then do something different without really knowing what.
Sure it would have been great had he felt that he had another great, public venture in him but he didn't and I don't think there's anything at all to criticise in what he did or how he did it. That's not saying he's a saint (I think he unwillingness to speak about almost anything since is slightly off, though it is his right), just that I don't think he's done anything to deserve criticism in the way you're suggesting.
Obviously it diminished any legacy Garfield has had but he's still got to go and do what he wanted (Orson's Farm).
But it's not clear that Waterson's something else would ever be commercial or public - just that he was going to go and do something that wasn't Calvin and Hobbes.
Only he will know what his original intention was (or even if he had any sort of clear idea at the time) but he has no children and is presumably financially secure for life from Calvin and Hobbes so at the very least he'll have known that not "working" again was an option.
He's married but has no children and seems, from what you can read, to live a relatively modest life.
I'm assuming that adds up to being secure and I suspect if it were to go one way or another from secure it would go towards being very well off indeed.