History has shown that completely deregulated markets lead to either a monopoly or a cartel.
Um, in case you haven't noticed, the cable companies are _already_ monopolies, granted by the government. This is the problem we are trying to solve!

The parent poster was not advocating repealing antitrust law, as you seem to have convinced yourself. He was simply saying that getting rid of regulation that grants the monopolies in the first place would foster competition in the cable access space, which would be beneficial to the consumer and to the progress of the industry as a whole.