Of course I've seen loop index comments, and redundant variable declaration comments, and all manner of bad commenting. Thing is, I'll take a bad comment over blank code any day.
Crap comments warn me ahead of time that I'm dealing with a developer who's either too inexperienced to know how to comment well or too sloppy to do a good job at it and in either case I need to be paying closer attention to their code than I might otherwise.