If I had the option to not pay taxes, obviously I wouldn't but I don't that that has any relation to tipping.
On the other hand, when the government asks to donate for a disaster, does everybody contribute even if they completely sympathize with the issue? You may do it sometimes, but will you do it every time there is a disaster? Will you do it even if you can afford it? What will be your opinion of the government if they tell you "We can't deal with these disasters unless we get donations. We know these same disasters happen every year and we should have budgeted properly but we didn't do it for political reasons. But now if you don't donate, people will be in trouble"
Tipping is a way of showing your appreciation for service. But if it has to be done every time, then you may as well call it a service charge.
On the other hand, when the government asks to donate for a disaster, does everybody contribute even if they completely sympathize with the issue? You may do it sometimes, but will you do it every time there is a disaster? Will you do it even if you can afford it? What will be your opinion of the government if they tell you "We can't deal with these disasters unless we get donations. We know these same disasters happen every year and we should have budgeted properly but we didn't do it for political reasons. But now if you don't donate, people will be in trouble"
Tipping is a way of showing your appreciation for service. But if it has to be done every time, then you may as well call it a service charge.