Of course there's a market for it. Do you not have at least a few friends who are holding out with their candybar dumbphones or antique iPhones to this day, citing reasons that include but are not limited to 1) I'm not wasting money on a new phone that will have to be replaced every year 2) I hate how much trash electronics generate 3) I want to be more engaged with the people around me so I want my phone to be less capable/less distracting 4) I don't like facebook and the NSA spying on me and I won't get a smartphone unless I'm sure they can't.

I have a good handful of such people in my social circle, ranging in age from 23 to 58, usually higher education levels, and usually non-technical. The biggest common factor amongst them is that Android doesn't work for them.

> Do you have any evidence such a market exists?

Yes. I have evidence there is a market for this, consisting of 1 or more persons, willing to pay at least $0.00.

Not every OS needs a 1-2 billion users install base.

It exists. Desktop Linux exists, works well and maybe has some single digit market share but in a market basically consisting of everybody and their dog this is still an impressive number. It may not be enough for global megacorps but enough to be sustainable.

The most successful business created industries for themselves. In ollieparanoid's case, he's creating a secure and supported OS that runs on any phone, and when you consider that 90% of phones are missing a secure and supported OS, then that market is pretty huge. If this works then his OS dominates any old, unsupported phone.

People don't care about open source and sustainability but they care a lot about not being hacked and having a phone that runs, and runs fast.