It's not a free market. There's a witness discount. 

 "Free market" doesen't mean there is no transaction costs. There has always been a minting and verification cost to real money. Trusting the government to catch counterfeiters is no free-market solution. 

 Also, you do realize Bitcoin isn't a free market for whatever use case, right? 

 Free markets require rules in order to function, so it's not unreasonable to ask if those rules need to change.

Not saying that should happen for inscriptions (it's probably not worth it, just let them keep donating to miners until the fad passes), but free market doesn't mean anything is allowed as long as you pay enough. 

 Well, if nation states tax their citizens to pay the miners to fill the blocks with garbage then this could actually work as an attack on Bitcoin, at least for a while. It can get ramped up or down from one day to the other, so it could go on for weeks with "random" pauses as needed. If randomly every other week, Bitcoin turns unusable, it will loose a lot of users.