>>13995969Because it's a balance thing. Poison is only bad because it's too heavily outclassed by Steel. Outside of that, it's pretty great defensively, better than rock, but Steel is such a defensive beast that does so much better than poison, people stopped caring. It's probably the fourth or fifth best defensive type under Water, Dragon, and Steel.
Ice types are shit defensively because ice moves are pretty fantastic offensively. Sadly, they're so good that they don't even need to be on ice Pokemon in order to be good anymore.
Normal's meant to be mediocre. Dark isn't that bad considering it's mostly based on utility (Night Slash for crits on absol, sucker punch priority, pursuit trapping, thief item stealing, bite for technician flinches, beat up for gimmick justified, etc)
