I imagine what the OP meant is that when you feel you are wasting time on Social Media, if you say "I am a winner / I am better than this" (or something more positive), it will block the social media for you. So basically the reverse.
What suggests that shouting "I am a winner" is less annoying than shouting "I am a loser"? In fact, not just less annoying, but it has to be pleasant as in that scenario you would have to scream it while you are already struggling with impulse control. Even the slightest reason to not to do so would see you not do it in that type of situation.
Why do you think that their free tier is not great? AFAIK, it works like any other free tier email service but with encryption. Though it does have a limited storage space (which has increased recently). Anyone who would need more than that & has chosen to use PM probably also understands the cost of free products available & will be willing to get paid service
Disclaimer - I am a paid PM user (converted from free tier after using it for few years)
Signal Foundation is a non-profit. It is my understanding this is a 0% interest loan, not an investment. I'm no expert, but after examining their 2019 balance sheet, it seems to me like they are well on their way to paying it back.
I guess the salaries are competitive in San Francisco. Spicy!