Y'know, Killer Moth really should be a better, more respected villain, not a lame joke of a character.
The concept, as presented in his first appearance in Batman #63 (February-March 1951), is simple and straight-forward: a costumed character that does for crooks what Batman does for the honest citizens of Gotham (though, of course, there are some differences . . . like the fact that Killer Moth charges for his services).
But, alas, despite a few appearances in the 1950s, he never was quite the same when he appeared in the 1960s and 1970s.
Don't know if it was his . . . questionable . . . fashion sense or what, but after being taken down by the efforts of the neophyte Batgirl when Barbara Gordon first appeared in costume, he didn't really get any respect at DC for a while.