Who's being "taxed" without being represented?

Dash holders? Simply holding Dash comes neither with a "tax" nor any income to be "taxed", hence no right to be "represented".

Miners? They vote and are represented by their hashing power and the client-implementations they use. If they don't like a proposal they can let the network die (and relinquish any income ofc) which is an even greater force than Masternode owners.

It's like saying "Australians don't get to vote on how New Zealand tax money is spent, unfair!"

Other than that I agree that the waiting period as well as the participation rate should both be raised.