To be successful it would have to be so fucking great as to outshine Apple but have a price that rivals Blu. Let us not forget that Microsoft tried this same approach with Windows 10 mobile at decent price points, some phones under 100 bucks, one system for all with a Universal language UWP where apps made for the phone would work on Windows 10 store and vice versa... nobody would develop for it and now Microsoft has abandoned phone, supposedly just for now.
Yeah, it's quite a market to try and break into. I really enjoyed my Windows phone but the lack of development and ending of support for what there was just made it become almost useless (then it died so became totally useless). A Linux phone is something I'd like to try because I like trying alternative things like that but they really have to have the every day apps.