Google and Verizon sitting in a tree

Google and Verizon propose a Net neutrality framework. From Marguerite Reardon in CNET News:

The major breakthrough in the proposal is an agreement that the nondiscrimination clause that the Federal Communications Commission has proposed as part of its regulatory efforts would be enforceable.

If it’s so good then why are other carriers and major players not lining up to help push the proposal into law? Maybe it’s only good for Google and Verizon.