I can sympathize with this. I work on a dynamic API security scanner, and the vast majority of the Parse APIs I've scanned have either used API keys with full read/write permissions on the DB, or have left the database in development mode, essentially allowing anyone with an API key to modify the schema of the database.
Parse was a very cool product, but most setups I've seen didn't take advantage of the (sometimes hard to find) security features Parse provides.
Not to disagree with your overall assessment. I'm generally wary of these swiss-knife frameworks - they're written for a particular use case in mind, and if your project doesn't fit that, you may go through contortions to get things working smoothly.
That's fantastic! I never kept track of which version(s) I worked on but I had transitioned one project from Parse to Parse Server and it was still able to work this way but I'm glad they made progress to try and force better security.
So instead of making HTTP calls to directly modify the DB you make HTTP calls to cloud code functions you wrote which then verify who you are and only modify what you should be able to modify.
The way everyone seems to use it, in my experience, is giving the client credentials to manipulate the full database which is absolutely insane. Obviously this is not good practice but every single parse project I've gotten thrown into already did this and it was a significant amount of work to move it to be more secure and NOT do that. I think the way it's created makes it very, very easy to make bad security choices.
It's also basically a RESTful CRUD. That's mostly it minus some, mostly minor, bells and whistles. You can already do this with about 20 different open source stacks very easily and you're not stuck using this parse technology.
I can't articulate just how much trouble parse has given me. I even took an app and re-wrote its entire backend away from parse significantly faster than doing a handful of updates.