There's a lot of hidden cost associated with supporting legacy features/standards/technology
Do they have different frequencies? Require different antennas?
Are there cost implications for radios / amplifiers? Do ASICs support only newer modes? How much obsoleted / legacy HW is required?
And that's just from a manufacturer standpoint.
Are more licenses required? Or other regulatory impacts?
Counterpoint:
You can say anything in an authoritarian state, the consequences are that you'll get disappeared in the night.