It's not just Snap, but Snap is the latest example of a bigger problem. For a while now Ubuntu have had a habit of trying to invent a new wheel rather than using their considerable resources to improve the wheel that the open source community is already working on. So you had all the time wasted on Unity instead of contributing to Gnome, all the time wasted on Mir instead of contributing to Wayland, and now Snap is just the latest example of them trying to push their own thing. There's also their insistence on controlling everything about LXD which is why it's forked off as Incus now, and so on.

Ubuntu could be doing a lot of good in the open source world, but they don't want to be involved in anything if they're not totally in control of it. So instead they're a black hole sucking up resources that could be used for better things.