I totally agree with that!
No problem, but what if more funds will be needed in the future for the development?
Many coins have such funds, and 93.5k XEL isn't anything substantial, but it can grow to nice $$$ over years, so XEL will have an advantage over other coins.
Why can't we vote it?
You cant vote to breach a treaty. Even if there would be a 90/10 majority it would be wrong cause in its initial terms it was exactly stated that those funds will be deployed.
But that being said, no one hinders you/us to setup another development fund that is donated voluntarily.
The voting for changing the supply isn't breaching the treaty?
For sure nobody gets confiscated his funds in a forceful way.
Altering the total supply might be a change to the initial plan, thats right, but i doubt that even in front of a court a claim would have any chance of being heard. Its basically nothing else than a https://en.wikipedia.org/wiki/Stock_split which happens everyday in the world of finance and is nothing to complain about as you are not being confiscated anything. While in your scenario someone would be forced to give away value that he didnt want to give away. Thats something COMPLETELY different.
But like i said there is always a way to do this by free choice. Also the devs could take some of those BTC and buy XEL with them, just to be sure to profit from an eventual rise in XEL value.