I suppose that's a matter of definition. I read "allocating computing resources" as "building/buying more hardware". That should indeed be unfeasible. But using social means to gather support from other people who have already allocated computing resources should be a lot more feasible.

Yeah, a lot more feasible but not less suicidal. The idea is that if miners were to band together to abuse their power and rig the system, the larger population would lose faith in Bitcoin's ability to accurately serve as an accounting mechanism, no longer value it, and Bitcoins would be worthless. Now the money the miners stole is worthless and their equipment is worthless. So it's suicidal for them to try to rig the system. They can't gain from it.