I used to hate metronomes too... until I started getting really involved in music. If I'm playing solo or in my regular orchestra, I hardly ever use one (if at all), but there have been situations where they've been life savers. In fact, one of those situations is happening right now, albeit not on piano...
I'm in the chamber group for my school's musical playing accordion. The musical is pretty standard, so I could listen to the CD, but the group only started playing together the beginning of the month of the play. The conductor normally conducts choir and has a VERY different style from the other musical directors at the school and tends to go back and forth between beating the measure and beating the quarter, eighth, or half notes. On top of that, since it's a high school production, the tempo of each song varies from the original, and the group has only started rehearsing with the cast the week of the show. The songs are fast and relatively unfamiliar, time is short, and the director is of little help. So what do I do? Use a metronome! Will it help while playing the show, when I have to adapt to dialogue and whatever else comes up? No! But will it help me bring each song as close to the actual tempo as I can so that I'm as prepared as I can be come rehearsal? Yes.
As others have said, a metronome can be a very powerful tool, but it shouldn't be a crutch. And in some cases, it's better to put up with the tedious and unartistic metronome than to fall into panic (like I almost did).
(PS something I thought of after originally posting this: if you're arranging a nonclassical song that only has chords or tabs, it can be difficult to figure out what the duration of each note is. A metronome can be hugely helpful for this purpose.)