At the time? 8-bit is still as incompatible now as it was back then. Polymer is the only renderer that displays the map perfectly (the bat chooses polymer and disables dynamic lights to maximize framerate), but classic isn't actually that bad. It only has very minor HOM and sprite clipping issues in the grand scheme of things, but we didn't want people to choose the wrong renderer and then complain about glitches so the bat was the solution.
And wow, yeah looking back a score of 90 is pretty damn crap for the map. It's easily better than a lot of other maps that have scored above 90. As far as I can tell Loke's biggest complaint (the point he devoted the most space to), was the mediocre framerate some people may have due to polymer, and possibly too many enforcer respawns.
It's a shame that Loke doesn't provide the breakdown that Forge uses so we can see more of the reasoning behind his low score, especially when Mikko gave it a 97 (probably on the higher end but IMO a lot more accurate).
Edit: Didn't see the last 2 posts when I posted this. Obviously I agree with and am in the same boat as everything Forge said.