As a PM, the other reason developers (or anyone else) doesn't like making estimates:
1) it's hard
2) you are accountable for them
No "My dog ate my homework" type excuses, no leaving at 5pm for a week and telling me on the last day your work will be late.
When you make an estimate, you are putting your credibility on the line. No-one is 100% perfect, but you should at least give meeting the given dates a solid try. Not "Whoops, didn't make it, can I have another week please?"
I think there's more to it than that. There are other things I do which are hard, and hold me accountable, but which are not painful in the way that software estimation is.
The difference that I see is that software estimation has a third component: lack of control. Every couple days Alice is going to stop by and say "you know we need feature XYZ, too, right?" (which was never in the spec). Then I'm going to overhear at lunch that Bob rewrote the account-management system so I need to rewrite part of my code to integrate with that new interface. And Charlie is going to walk into my office 3 times a day and say "hey, did you see the new video game?". Oh, and this release we're also upgrading to a new version of the foobar library, which works fine for everyone else but mysteriously crashes on my machine, so I spend a day and a half fighting that.
I love being held accountable for hard things. (2 quickdraws on the side of the cliff that I need to retrieve? Great! I'm performing a solo next week and I need to get up to speed on something I've never played before? Bring it on!) But only if I'm being held accountable for something I have control over. Accountability - control = pain.
1) it's hard 2) you are accountable for them
No "My dog ate my homework" type excuses, no leaving at 5pm for a week and telling me on the last day your work will be late.
When you make an estimate, you are putting your credibility on the line. No-one is 100% perfect, but you should at least give meeting the given dates a solid try. Not "Whoops, didn't make it, can I have another week please?"