The problem is Gnome seemed to look at mobile and "pre-sabotage" itself. Both Gnome 3 and Unbuntu Unity wound-up creating "tablet/mobile ready" shells when no one was going to be using them that way. Tablets only seemed to be the wave of the future because they were new and everyone was buying them. It only became evident later that laptops were going stick around for a while and be what most people still used if they were doing "real work".

But with the narrative being "this is the future", they were more or less pressured into it. The designers as well as programmers are volunteers and I would imagine designers want to work on the "cutting edge" even if that cutting edge is a complete disaster for users (just Microsoft's redesigned UI was).