Is it possible for YAGNI to apply in the past tense? You created some functionality, it was used a little bit a while ago, but you aren't using it any more, and you don't want to maintain it, so you'd rather delete it.

Is getting rid of unused or rarely-used functionality neccessarily a bad thing?

Background:

• I use source control, so if I need the functionality again, I can get it.
• I'm the only user of my software (I'm a bioinformatician analyzing a data set).
• One scenario where I came across this was that I was using inheritance, with a parent class, and two child classes. One was handling files generated by 454 sequencing (next-generation sequencing), and the other was handling files generated by Sanger sequencing (previous-generation sequencing). I was actively maintaining the latter, but not the former. Maybe my mistake was using inheritance rather than composition, but that's a slightly different story.