domain squatters are already an issue. imaging if you could register domains for free. I think having to pay $10 for a year is pretty fair. That's one reason I don't mind paying ~$70 for .io domain. it keeps most squatters away.
The problem is the horrible user experience of registrars like Godaddy. I'd rather give my money to a nonprofit that isn't confusing non-technical website owners into buying products they don't need.
The registrar landscape is better now with Gandi, but still I'd rather pay a fully transparent nonprofit registrar if one existed.