The point is that Free Basics existing would automatically remove a huge amount of incentive for other solutions appearing. Why bother building a better internet if FB already provides "the essentials" to everyone? It would wipe the market before it had a chance to develop organically as it happened elsewhere. If AOL had provided free access to its own services only we would have a very different network today.
CompuServe never had the volume and appeal FB has today. Minitel is a good reference because it is widely credited as one of the reasons France initially experienced slow internet uptake.