Comment by Nifty3929
"... and they're paying for it..." - that might be the exact issue. Google has no way to ensure that these small shops and startups will pay their bill, so quotas are used to prevent the company from running up a large bill they won't be able to pay.
I see a bunch of threads on reddit about startups accidentally going way over budget and then asking for credits back.
This doesn't at all mean the startups have bad intent, but things happen and Google doesn't want to deal with a huge collection issue.
If someone rolled up to your gas station and wanted to pump 10,000 gallons of gas but only pay you next month - would you allow it?
Well that is kind of a problem of their own making. The clouds refuse to entertain the prospect of pre-paying for services/having some sort of hard spending limits because they know that over-allocation is probably driving a decent amount of revenue.