HTC Incredible :: Forced Install Of Froyo On Unrooted Motodroid?

Why does the Inc have to be rooted in order to install Froyo? My Motodroid1 was able to install a leaked Froyo without having to root. Is there something more difficult in the software that the Inc uses or is it the actual leaked versions were never designed for an Incredible or what? I really don't understand why we seem to be lagging the Motodroid community in being able to install this. I'm sure someone has a perfectly good explanation and I obviously don't have a clue. I am a newbie with the Inc and I did love my Droid1 until it got run over and no replacements were available. I have to say that so far I am not that impressed with my Incredible. It's slimmer, I rarely used the slide out keyboard on the Droid 1-so I don't miss that, a few things seem to respond a little quicker, but overall I liked my old Droid1 better. The 2.2 I forced on the Droid was a huge improvement over 2.1. The 3d gallery glitches were gone, the mass updates were great, camera worked super. Battery life was always excellent, pics were clear, no dropped calls, always had a signal. Output volume to headphones was a little weak on a motorcycle but I solved that with a nice little pocket amp. I don't mean to knock our phones but... I never had to worry about battery life, poor signal strength,etc. And I miss the 3D gallery after the fix but I did find a thread here to help me install it in the Inc. When 2.2 gets here it should be a nice improvement but I wish battery life wasn't an issue and signal strength was better. I don't feel like spending some pretty good change for a high output battery.