Cool your boots, the rule book isn't you're problem, it's you're local meta game, you can't cry out for the nerd stick because of it. What you do is adapt and counter thier list. Facing rhinos and chimeras? Load up on Hive Guard, got Land Raider trouble? Get some Zoanthropes on the go. 40k is a very Darwinian game so all you can do is adapt and counter in a cycle that keeps the game fresh. I've played since 3rd and I think this is the best edition yet.
As for mech, sure it's normally the most efficient option but it's not the only one. I've played against foot slogging CSM before and that was a challenge, there were so many marines...
Follow mine and Jam's 40K delusions at: