The problem with setting it to "donations" is that people are cheap and forgetful. I've seen people throw money at copy/paste kernel devs to get them a new phone year after year only to abandon it for the newest phone because they got that donated to them. Rarely think about the people that brought them the stock files they use when they mess up their phone and save their investment, or the people who port recovery and the teams behind the recoveries, the folks who make it possible to flash all your roms/mods/kernels etc.
Obviously the way things were, weren't working out, otherwise they wouldn't have switched to it. Bounties go unpaid by almost half of the people who say they will pay, add into that this was done by a team means that money has to be split. so lets say this $250 dollar bounty, every one was perfect and paid it and it was split 3? 4? ways? that means that to each of the devs who poured countless hours into it would get about the cost of the cdma phone to provide an entire community freedom and ensure their devices can last even longer than what official updates will provide.
The android community is growing and the number of people who donate is IMO staying the same or growing smaller. Ive ported recovery to 7+ devices this year, ported Cyanogenmod to one, and rooted two more. I had to purchase one of the phones i rooted but it wasnt in danger of bricking or actual risk. these guys have put some serious time and effort into it, and btw anyone who is trying to pirate it id seriously reconsider unless you dont value your device.
I really dont care about this phone being rooted anyways since I store a few grand in cryto on my moto g, and dont want that stolen xD. If I want an unlockable phone it looks like ill be headed for a GPe device or something so I would have to go through the hassle to be paying someone