If it's parking on public spaces, those are operated by the government, which inherently means it's not priced or operated by the free market.

And what if you're only parking for a few minutes in a private lot? Sometimes the minimum time you can pay for is substantially higher than the time you'll be occupying the space. 

 The owner of a private lot set the price and its minimum/maximum.
Don't like? Don't buy it.
That's the free market. Anything wrong with it?

Regarding some public parking space being free, yeah, I agree with you that it shouldn't be free.