Actually a 1% mining donation (of course this number is set in stone, I'm just using it because that's what BBR uses, I think) would make a huge difference to the development budget. In fact, it would mean there was a budget at all, which isn't currently the case for the most part. So a huge change.
It wouldn't need to be the entire source of funding, but as a source of some steady funding it is sufficient enough to consider on that basis alone. Working out the numbers it comes to about 2500 USD per week at current exchange rates. That's enough to pay for a few days of full time dedicated development, which we are currently not able to do on a sustainable basis, and is certainly enough to accelerate progress significantly.
I think the really important point to drive home is that, atleast in the bootstrapping phase, there is nothing "wrong" with this approach. In almost every other industry in the world, when someone develops a product they charge for their services. No one makes a pair of shoes and puts them up for free in the store and hopes that someone donates. They make the shoes, put a price on them, and then people decide whether or not they want to make the exchange. There is no good reason why crypto developers shouldnt be entitled to do the exact same thing as a shoe makers for the exact same reasons why shoe makers are entitled to do that thing. Consumers arnt "forced" to pay this fee any more than a customer at walmart is "forced" to pay for the products that are on the shelves.