Nothing at all funny about the ad. Because, the only people who think “gear doesn’t matter” are those who have not held a high end camera. What people ought to be saying is, “it’s only part of the equation”. Certainly a 5D3 is useless to someone who has no training or talent while someone who does will certainly outperform them with a 40D.
In any case, I most certainly want my second shooters to use the same camera that I do, and that’s the 5D3 (at this moment anyway). I want output and consistency as I don’t need to spend extra time processing output from some other camera. I also have an expectation of the output and do not want to be processing images from a 10D. Gear does matter. If it did not, Canon would never sell anything over their Rebel line. I don’t follow the other brands but again, the same follows. Along with the body, there are lenses and flashes that come into play.
As far as getting used to another brand, I guess it’s possible. YMMV but for me it would take quite some time to get used to Nikon’s backward lenses and weird button placement.
Again, I see nothing wrong with asking for someone who is familiar with the gear so that there are no mistakes made or time wasted by someone unfamiliar with it.