I wouldn't say he doesn't care enough to make changes to the game, most if not all the changes aren't easy to make and quite frankly aren't necessary, especially coming from someone who doesn't owe you anything at all. He just brought the forums back for the sake of the community that still exists, he literally could've just said "forget it" and just left it dead.
I don't mean any disrespect towards Eric Hartman himself. I am very appreciative of what work he has done, and I totally understand if he doesn't want to give Blockland any attention any more. It's been over a decade since he initially created this game. Any creative person would be burnt out by this point. I would completely respect his decision for abandon the game, should it come to that. The fact that he still gives any stuffs about this game and its community after this long is admirable. I have no personal vendetta against Eric, nor do I think he owes me anything.
Eric shouldn't have to keep this game running forever. I--and I hope others too--want to do what I can to keep this game going, and perhaps breath some new life into it.
most if not all the changes aren't easy to make and quite frankly aren't necessary
I hear you. Vehicle physics are a prime example of this. The issues we see with them are pretty much intrinsic to the engine. But that is precisely the kind of problem that could be fixed by recreating with a newer, better game engine.
And just because a change isn't "necessary", that doesn't mean it wouldn't improve the game. For instance, I think it would be great if things like Slayer and various brickpacks were built into the game, despite being unnecessary.