I think the issue people have with the 5c is instead of getting the actual iphone 5 for 99/549 they got a cheapened version of it for no discount. People feel like they got jipped. It should have been the same price as the 5 normally would have gone to if they hadn't released the 5c.
To make matters even worse, the nexus 5 is about to be released with better materials (soft touch plastic vs glossy hard plastic), a much better cpu, and a bigger better screen for less money. With arguably the best software support in the industry. Nexus phones not only get all the updates but unlike apple where some features may be reserved for the device the ios version launched with, nexus devices get every feature in the new operating system. Nexus phones also come with a fully unlockable bootloader (without the need to register the phone like some manufacturers). Not only that but they come with the full source code to the OS, etc. The software possibilities for them are pretty much endless. And if you just want root and don't care about custom roms, the unlocked bootloader also means you don't have to wait for an exploit to gain root. You just flash the superuser binaries. There are plenty of one click tools that will do this for you.
Overall, the nexus phones fit both people who love to tinker and change everything, but also people who want something that just works as well. That is a very difficult combo to attain. Now if google could just get the carriers interested enough to sell them directly without molesting them. Atleast my Verizon Galaxy Nexus is officially in AOSP. I have a fully functional and stable 4.3 build on it. The sprint variant isn't in official AOSP and they have yet to get 4g data working on 4.3. The Verizon model was good to go on day 1 of the 4.3 release. Ideally, google would sell one variant and the updates would be handled through them. Carriers would be free to subsidize them, but the software build does not get touched. Everyone has the same software.