This isn't just a matter of throwing money at the right people. Its part of a larger ideological debate about how to regulate the telecom industry. The trend over the last 20 years at the FCC has been rooted in conservative economic thinking. Deregulate the industry, use auctions to allocate spectrum, etc. The 1996 reforms didn't achieve everything it was billed to, but the fact is: 1) at the end of the day, Washington views it as largely successful; 2) the state of the internet in the U.S. is competitive with other large western countries: https://news.ycombinator.com/item?id=7709948. The telcos certainly don't lack numbers to point to to show the competitiveness of the U.S. industry under the existing regime.
Net neutrality is a hard sell because it goes quite against the prevailing thought at the FCC. It has the support of many netopions, but not really among the mainstream/conservative economists that carry the most weight in these policy debates.
The internet companies need to lobby, sure, but they also need a "hook." And "openness" and "neutrality" which are words that resonate in Silicon Valley on their own are not ones that resonate in Washington.
To compare, look how the environmental movement has responded. Environmental groups don't talk about "conservation" and fuzzy ideas like that, not anymore, not in Washington. They talk about externalized costs and concrete economic phenomena that justify regulation. The tech industry needs to ground net neutrality in something like that.
Incidentally, this is part of a debate that has been raging for 30+ years. Telecom and wireless regulation has spawned thousands of journal articles and thesises. Politicians don't read these things, of course, but they're hugely influential to the technocrats that do the first draft proposals. At least to the extent they can back ideological viewpoints with a theory-based narrative.