It's not hard to define a quota system and enforce it. If the quota is too high then reduce the quota. If people are abusing the quota with automated requests then detect that and rate limit those users.
If I'm paying $200+ a month I should be able to saturate Google with requests. It's up to Google to enforce their policies via backpressure so that they don't get overloaded.
Then again this is the same company that suspended people's gmail because they sent too many emotes in YouTube chat. Sadge.