You can use the plan without writing code
A paid plan covers file jobs as well as API requests. You can use it entirely through bulk uploads or share it between files and an integration.
You can subscribe to ParseAPI and never write an API request. If all you do is upload spreadsheets, that is a normal use of the plan.
I wanted bulk to be useful as a product on its own. Someone cleaning a contact list should not have to learn about API keys before they can decide whether to use it. The API and file tool perform the same checks, but the way you get your work into them is different.
On a paid plan, sign in and upload a file through bulk. The quote uses your team's included allowances. Checks that support additional paid usage follow the same settings you manage on the Plan page. You do not need to copy a key into the file or configure an integration.
You can use the plan both ways too. Suppose your application verifies email addresses as people sign up, and someone on your team uploads a list from an event. Both draw from the team's email verification allowance. There is no separate file allowance waiting in another account.
That was the reason to keep one set of plans. A file is another way to ask for the work, and it should not force you to choose a different product or subscription.
For an occasional file, the one-time checkout is still there without a paid subscription. For someone who uses files regularly, the subscription does not need an API integration to justify it.