I agree that cryptocurrency is largely a cesspit of ignoble intentions even if the mathematics are interesting.
I see our mission as trying to improve the safety of Linux for its users. Obviously Ubuntu is a significant share of those, but we should think more broadly - our goal should be that anybody using snaps from the official snap store on any distro should be safer than if they were getting that software from other hosting platforms. We are increasingly living in a dangerous world where one is almost certain to want to run software from untrusted sources, whether that’s downloaded and installed apps, or web page scripts on a website at a link you just clicked on.
While there are ultimately limits to what we can achieve, I think it’s fair to challenge ourselves to consider additional measures that raise the safety level even if they will never be perfect.
In the design of snaps and the snap store we have mainly focused on technical confinement - the idea of safety being limited to ‘blast radius on the system’. We’ve built the best way in the world, imo, to constrain which files an app can access, which APIs or kernel services or network locations it can use and by extension attack, or be a vector for an attack. Those are measures for technical resilience.
In this case, we need to think about social resilience - how to make running Linux safer for people who are themselves vulnerable to social engineering. This is a very hard problem but one I think we can and should engage in, otherwise we’re not helping a user to help themselves, even if ultimate responsibility does lie with those users.
I don’t however think that banning cryptocurrency apps helps. If anything, it would make using Linux much worse.
At least snaps have good, and over time increasingly good, mechanisms for technical confinement. Projects like Ubuntu and Debian and RHEL have relatively rigorous know-your-contributor processes, but apps can’t all be in the distro archives. The other Linux app distribution mechanisms (such as PPAs, Github builds and releases, OBS, or even the containerised ones like Flatpak) don’t have nearly the same technical measures for confinement that snaps do. If we ban cryptocurrency apps from the snap store then those users will simply get apps from those unconfined sources - and then the attacks will be even worse because the apps can go trawling all over the system, or do things like keylogging.
At least with snaps we have more measures to limit attacks to social engineering, or defects in the kernel and related confinement code. So as much as I would not put my own money into a crypto account, and would strongly recommend others to avoid them, I don’t think banning those sorts of apps from the snap store is helping Linux users, it’s just forcing them to be even more exposed when they use cryptocurrencies.
My colleagues have been fighting a quiet war with these malicious actors for the past few months, and are working to strengthen our hand on a number of fronts. They are working up a more formal statement and I won’t pre-empt it here, I just want to express the view that pushing our users to less-safe software distribution mechanisms isn’t helping them.