Printable make posting locked behind purchase?

Are you in their buyable models section? They recently opened up a way for creators to sell models.

How does this make any business sense from any angle?

Presumably, you have the actual file already, but you can't give some free advertising to the creator by posting a make of the file? Locking the file behind a paywall makes sense since that's the actual thing of value here. Locking a make behind a paywall is neutral for the consumer and a negative for the creator.

From the consumers' perspective, there is essentially zero incentive to pay just to post a picture of someone else's creation. There's no FOMO, there's nothing being 'withheld.' It's just one less step you have to do (assuming you wanted to do it in the first place).

So what happens here is the creator loses out on free advertising, the consumer isn't even mildly inconvenienced, and Prusa still gets zero revenue out of the whole deal.

Can someone give a rationale for this? Maybe something I'm missing?

You should ask the creator. Maybe he's unaware that people can't post makes anymore or it's a setting they can change.

Not to name and shame but what's the stl link? I've never seen this before and I'd like to.

Had this happen as well with the GR86 trunk handle file that's on there as well. I made a make, tried to mark it as such, but was given the same error. Like with your case, the creator doesn't have an option for purchase/support.

Some aspects of Printables are "wrong". Contests are a total mess at the moment. I might make a serape post about it.

This? Looks like a glitch/bug. As far as I can tell this is only active on paid items which makes sense.

I wonder if this is a sign of Prusa grasping for any revenue stream to stay afloat after they sat on their hands and let the rest of the industry leave them behind.