Serves no purpose, annoying, the most boring character in all of star trek....
That's original enough to suggest that you might possibly have an answer for a recurrent mystery in Voyager commentary.
How can the half-dozen Harry Kim episodes be such a problem? Cutting them out of the show wouldn't make it noticeably leaner or faster paced.
How could a token character who spent little time on center screen possibly be so boring? Unless the viewer has a remarkably short attention span, an interesting character is almost certainly going to appear by first commercial break, if not sooner.
If the Harry Kim character is such a nothing, how come he can't be ignored? The same question applies to Garret Wang for those who think they see some apocalyptically bad acting.