Subscriptions are going to leave you open to changes in the subscription terms at any time. This is especially true of AYCE subscriptions for something with a substantial marginal cost of additional usage.

If you want unrestricted and unlimited usage, it's available through the API. Complaining about the subscription like this is basically saying, I want what you're offering, but I demand it for cheaper than what you charge for it. That doesn't make any more sense here than it does at the grocery store.