Domainers do not and cannot charge premium renewal fees, and there is a HUGE difference between paying $5K for a domain and having to renew a domain each year for $5K. People grumble at the first one, but get out their pitchforks and torches for the latter one.
It's like buying a house, and then each year you have to pay the entire purchase price of the house in taxes. Insane.
There are registries that charge premium prices when buying select withheld domains, but have standard renewals, and they don't get much, if any, flack at all. Great domains are a premium item worth the money, but premium annual renewals is just a scammy cash grab.