I would say if you have strong feelings that you do not want to root than you should not, but if you are on the fence like I was once you do it, you will question why you did not do it sooner.
There are one click methods out there to root your phone, so you don't have to do any coding or anything along those lines, you just hook your phone up to your computer download a file or two and then follow very simple instructions and you are rooted. I used rootzwiki method, but there are a few out there.
The best part rooting your phone does nothing to your phone. It gives you access to do things that you could not before, but you don't have to do any of it. It also opens up other applications that you can not use unless you are rooted. The best one is Bootstrap Recovery, where you can make a back-up of your system and then reload a back-up at anytime if you mess something up.
Once you get use to it you can Overclock you phone, to get more out of your processor and make it run smoother, or use less voltage to have the battery last longer. You can also add themes or a ROM to your liking, but you don't have to.
Lastly now that there is a 2.2 SBF out there, there really is nothing you can do to your phone that you can't undo and get it working again.
To me the reasons to be rooted are the overclocking, they have made my phone amazing, it is so fast and there is no lag. Being able to have the back-ups which I have only needed once, but it is nice to have these so if you add an app that is bad, but you don't know what it was you can just go to a back-up before that and not have to wipe the memory and start all over. I also used AutoKill, but the ROM I am using has some settings already built in so I am trying it without for awhile, but that is also a huge plus. Also there is an Ad Killer app that you can get that will kill all Ads that come up on applications, really nice to have.
I don't know if this will convince you or not. I was on the fence and one day had some time and tried it and I can't believe that I didn't know if I wanted to do it or not. Being rooted by itself will not change anything that you do. If you are happy with your phone and don't want any of the advance features I would say don't root your phone. If you want the ability to make your phone better than you should root.