BT used to be a monopoly and it was hard for others to gain access because of what they had to do to build infrastructure to compete with that monopoly. Now they're not the biggest telco in the UK but they still control the fixed line infrastructure. Even that isn't strictly a monopoly in many places because VM offer phone service and decent speed broadband to compete, and by all accounts do so fairly well.
The US is similar to how it was in the UK in many places, there's a single incumbent supplier and you're stuck with their offering. Capitalism breaks down if you've got a monopoly supplier and a high barrier to entry, not least because the monopoly can always undercut new entrants who need to recoup their start-up costs. So if you want competition you have to help it with a bit of regulation. If you've got the newcomers complaining that it's not tough enough, and the incumbent complaining that it's too harsh, then you've probably pitched it about right :-)