Exactly. I'm doing this with the company I've been building [0] and it works. While it's taken a while being completely bootstrapped, we make enough money to grow and focus on our users. No one is obligated to track and stalk everyone online; that's just the prevailing business model (unfortunately).
Yes, and when you cash out to enjoy life in the tropics, whoever you sell to will then use any and all information you may have as they see fit, and load up your service with the usual. I won't even blame you for it, this is just how things work. I believe the sincerity of your statement of principles, just as I believe that Sergei and Larry were sincere when they told Google "Don't Be Evil". Everything ultimately has a price, even your principles, and even if it is very high, there is someone out there that will meet it if they can make a profit on it. The guys like Richard Stallman that are religiously committed to their beliefs is vanishingly small, and the odds that a founder such as yourself is one of those people is correspondingly low.
That doesn't mean I wouldn't use your service (which looks cool). It just means that I would have a plan in place for what I'll do when you sell out ;)
Haha well they certainly don't make the covers of magazines very often, but I don't know that they're as rare as you think. The people behind Basecamp, Balsamiq, and tons of other smaller companies are able to build "old-fashioned" businesses that stick to their principles and only answer to their customers. You need a little fortitude on the founder's part of course, but also the right financial incentives -- a key aspect the GP post missed.
As for Write.as, I spend copious time talking about why I built it [0] and making sure people know me personally, to address your exact point. Personally, I'm a simple dude who relishes putting more value on principles than a number in a bank account. And I'd rather have a tent in the woods than Mai Thais on the beach.
But we do have an open API [1] and one-click export to get your data out, so you can be sure :)
[0] https://write.as/principles