Actually, by being able to provide DSL service (and thus charge for it), the RBOCs would be much more willing to upgrade the physical plant (as the son of a planning engineer for an RBOC that serves West Virginia, I know this to be the case). As it stands now, there is no incentive for them to upgrade the existing plant even if more lines are required. And more lines means more centrally located switches (central offices) and thus better access to DSL.
The RBOCs have been under incredibly onerous restrictions that have been a tremendous drag on the spread of broadband and other communications technologies for far too long. This goes beyond these restrictions and into restrictions on providing video-on-demand, etc.
Amen, I'm a ST for a RBOC and the plant quality is going from bad to unusable. The RBOC's have no incentive to fix, maintain, and expand their current plant. They get taxed out the wazzo for it and they have to give it to anyone who wants to "borrow" it for cost.