Pegging to fiat isn't a bad thing in times like these.
When the business is getting paid in bitcoin, pays in bitcoin, and works only with bitcoin and its revenue is not dependent on bitcoin price rise/fall, it makes no sense to measure things in fiat terms.
I've made this argument elsewhere about gambling sites but it also works with mixers and any other business that is always working purely with bitcoin, maybe more so for mixers since their customer count increases unlike gambling sites. Kinda like this forum's donator status still costing 10
BTC.
With that said, I wouldn't be surprised if the rates were lowered at some point since we are still living in a fiat world where 1
BTC is not 1
BTC but is X$.
You are right from the bitcoin business perspective, and even from the principle, because this is the way to go if you believe in actual goods with fixed bitcoin prices.
However it can definitely come with adverse effects when it comes to the campaign participants. Because I believe they do feel the difference, and do act differently depending on the bitcoin price. Hell if it didn't cross my mind how crazy rates are right now. And I'm from a high paying country, with a good paying job. Now think about someone from a country with very low revenues. They might earn in a week what a good paying job brings in a year. That brings some kind of pressure with it, isn't it?