Ok. I get the strong sense† that Fried and DHH are in love with 37signals. Which may be why they haven't bailed to shoot the moon yet.
So when you say something resembling "you'd expect to see companies like 37signals trying to roll the snowball into something like Twitter but that rarely ever seems to happen", I'm inclined to point out how that misreads the dynamics of companies like 37signals.
† (won't bore you with details, but I have many of them)
I think Fried and DHH are already shooting for the moon in their own way. The kind of people who shoot for the moon are generally not just looking for money, they are looking to "change the world", they are looking for fame.
Fried and DHH make enough money from 37signals. They are shooting for the moon by contributing to open source and writing bestselling business books.
So when you say something resembling "you'd expect to see companies like 37signals trying to roll the snowball into something like Twitter but that rarely ever seems to happen", I'm inclined to point out how that misreads the dynamics of companies like 37signals.
† (won't bore you with details, but I have many of them)