I think this is maybe intentional, because this allows for some interesting strategic possibilities, even when it is a bit odd at first glance.

Realism is a poor argument for a game which features talking hedgehogs firing bazookas and melon bombs at each other.

It is something that we know about, yeah. And I do enjoy using that strategy. Esp on dangerous ledges.

It's the fact that it is interesting strategically which is why there's no check for obstructions there.

Also I guess is easier to implement as it currently is.

And, yeah, lots of stuff isn't terribly realistic. One of the things that harms playability for noobs is the whole "shots originate at centre of hedgehog" thing, but fixing that properly would involve making the AI code quite a bit more complicated and would require checks for thin walls if your bazooka tip was poking through 'em.

I guess fixing this would be appropriate in terms of consistency and "least surprise" but, eh... is still fun to do, so I'm not going to change it.