Currently I'm on Insert-coin ROM running Gingerbread and Sense 3.0 which wasn't supposed to run on Desire at all(Sense 3.0), but here it is running smoothly.
Wildfire S has got 600MHz Processor, 512MB RAM & 512MB ROM and ships with Gingerbread, Desire has 1GHz processor, 576MB RAM & the same 512MB ROM and yet it hasn't got enough ROM space to handle gingerbread?
Those into Custom ROM's know that using Aplharev, ROM Partitions on HTC phones can be modified to suit different needs, HTC can release a patch or something to modify those and have enough system partition to handle GB.
Even better, there are numerous ROM's which don't need any partition table changes and installs into default ROM layout. If they can do it, why can't HTC??
Simply put they don't want to waste time in developing firmwares for older devices, which is unlike HTC in the past, since they have always been very aggressive in pushing new updates to all its models irrespective of Old & New.
Regarding locked bootloaders, Yes, they have
announced that future devices won't be locked, But why lock it in the first place and now trying to fix it with a patch. Why waste time in such useless stuff but they don't have time to push firmwares for Desire!!!!