I agree with your overall point and am not trying to argue against it, but rather to provide an interesting historical fact: I happen to know of one example where this did in fact lead to nobody building telecom infrastructure in an area.

I lived in Albuquerque, NM in the late 90s/early 2000s when telcos were rolling out DSL infrastructure across the country. The local telco, US West, refused to do so (largely because their POTS network was aging and rickety at the best of times - the phone line hookup to my apartment building was still using old gel-pack connectors from the 60s), even after being taken to court over it, and happily paid $200k/mo in fines for a couple years to avoid doing so. It wasn't until US West was bought out by Qwest in 2000 that they finally rolled out DSL. I am generally extremely anti-monopoly so I think the break-up was definitely a good thing, but I attribute this to the break-up because a larger company would be in a better position to mitigate the costs of upgrading the infrastructure in one area with the profits from another or whatever.