And I'm not a difficult customer here: I didn't mind paying twice the price, or software issues in their custom Android version. I'm only moderately annoyed having a proximity sensor that keeps keeps needing a reset, a phone that keeps rebooting for no reasons or a pretty bad power management (going from 15% to no-battery in less than a minute). They are a small company and have limited manpower, I can totally understand that.
What I'm really pissed off it them not fulfilling their promises. They sold me a modular phone, with the promise of hardware upgrades and maintenance. They sold me a “PC”-like smartphone, where there's no frequent release of new models but a continuously upgrade-able phone. But they didn't even try to deliver, and they didn't apologize.
[1]: in 2016, and I'm still using it btw, even if it's far from good at this point, because it “works” and I'm still pretty conscious about the environmental impact of smartphones.