If Ruby on Rails causes nothing but headaches for those who insist on silly frilly things like data integrity, I will theorize that perhaps the problem lies with RoR, not foreign keys.
You probably don't actually need a database at all , given that the integrity of data stored is not paramount. You don't get any points for "We have this data. We have no way of assuring it's correct or is what we want it to be - but we have it!"
On the other hand, given that most start-ups don't bother with things like a business plan (at least one which doesn't end with "Step 3. ????? Step 4. Get bought by Google"), perhaps it's only appropriate that such start-ups do away with other fundamentals of reality, such as data integrity.
You probably don't actually need a database at all , given that the integrity of data stored is not paramount. You don't get any points for "We have this data. We have no way of assuring it's correct or is what we want it to be - but we have it!"
On the other hand, given that most start-ups don't bother with things like a business plan (at least one which doesn't end with "Step 3. ????? Step 4. Get bought by Google"), perhaps it's only appropriate that such start-ups do away with other fundamentals of reality, such as data integrity.