TotalBiscuit sums it up nicely for me: Link
Basically covers everything. Can't believe I watched the whole thing. Now I'm gonna be late for work.
I think the difference is that you know that when ordering GTA5 that you are going to get a completely working game. With these early access titles, all you have is the promise of a working game sometime in the next 2-5 years which may or may not ever happen, yet you don't get your money back if it doesn't. If I pre-order GTA5 and they cancel the game before it's released, I get my money back.
There has been AAA titles that had an option to play early also.
Same for Steam pre-early games, if they do not get released then you can get your money back.
People just think bad straight away, "oh no Stomping lands is not updating and the guy ran with the cash.... must mean all other early play games will go the same way...", that is of course not true at all.
Personally I just feel people just don't have any patience or positive thinking these days.
ADDENDUM: Jig the developer of Stomping Land has since released 2 Patches, so it does look like he is working on the title. In case people didn't know and wanted to check out the patches if they have the game.
[Edited by DABhand, 9/27/2014 7:01:50 AM]