The problem with saying that the Ramones were the most influential band of the 70s is that still, 30 years on the Ramones still have nowhere near the exposure of the Beatles, or Led Zeppelin, or The Eagles, or Fleetwood Mac, or AC/DC, or any of the countless others that ruled the decade. Shit, the Beatles were coming off Abbey Road in 1969, and its influence and sales surely stretched farther into that decade than all the Ramones records have in all the decades since. Even the Sex Pistols were probably more widely known and (thusly) influential than the Ramones based on the sensationalist press/exposure they were given at the time and since.
Its sucks, and its obvious that a room full of punk/counterculture music fans would disagree, but any of those bands above, or the other ones like them (Simon and Garfunkel, Beegees, Pink Floyd (Darkside era), Led Zep (hugely influential on the entire heavy rock/metal scene that still is far more popular than punk/indie anything, not just preening hippy frontmen), or Michael Jackson by the tail end of the decade (and who completely ruled the 80s, without any debate) were the Beatles of the 70s. If not the Beatles themselves.