I get what you are saying, and I've seen that too, particularly with big corporations buying small companies or independent developers with a great product. I think what's different here is that Proton is not Microsoft or Google or Apple. It's not some megalithic closed-sourced corporation with massive layers of management and thousands of shareholders to please, etc.. Proton is still basically an independent developer themselves and actually *very* small in the scale of things, especially when people bring up examples of big tech. They are also very much in the open source community side of things, which is overall a different culture than anything like Microsoft, etc., so there's just no direct comparison with those here.
Even a comparison to Fastmail buying Pobox is not a perfect example (although it's a better example than Microsoft vs Proton) -- Fastmail is *mostly* closed source and that's a specific culture difference. Fastmail is employee-owned (last time I checked) and yes, they do participate in the open source community with Cyrus and JMAP, so there are comparisons there. And I don't think Pobox suffered under Fastmail's ownership, except from what I understand, their customer support went down. However, Pobox has benefited in other ways, so maybe it's a wash for Pobox.
So I get your point, and time will of course tell with Proton and SimpleLogin. You could be right. But I think in this case there's no red flags so far that will happen, but rather good signals about audits, security, infrastructure, integrations... that's pretty good stuff. I think they've also indicated that there will be special deals both ways, so that's good for the customer's pocketbook too. But who knows?
Now if Proton stifles Son Nguyen Kim (the main guy at SimpleLogin), then that would be a red flag of course and I'd tend to agree there could be problems ahead. But as of April 2022, seems like it's a healthy match. Will cross fingers and stick with custom domains!
