However, an equally ridiculous set of assumptions can be used to take over a PoW chain. So this is not anything specific to PoS, it is social engineering attack mixed in with mass hypnosis. Why not simply the attack where you ask everyone to just send you all their funds? That would work too
What you call 'ridiculous', I call rational behaviour.
The OP shows one example of how this could be profitable, so 'economically unviable' is also unjustified.