I'm not surprised. We went to check out their Monacos a couple of months ago. The salesman we talked to was quite rude, and we left thinking that even if they a had coach we liked (they didn't), we wouldn't deal with them anyway.
On the other hand, when we went by Grin's, also in Morgan Hill, just to look at what they had, (fivers and TTs, used MHs) they were pleasant, let us poke around where we wanted to, answered our questions without pressure, and we had a very positive experience. I could see doing business with them if I wanted a new fiver.
Motorhomes, fifth wheels and travel trailers are large purchases, sometimes extremely large. It takes time and a lot of looking to figure out what you want, what you need, and what you can afford. Treating people like trash just because they aren't there to "buy today" is not a good business model, they won't come back when they *are* ready to make a purchase. I know I would be willing to drive, or fly 200+ miles to purchase an RV from a different dealership if the one found closest to me acted like the people at McMahons.
Just the two of us, and Falkor, the 2015 Ford 350 Dually, pulling a 2016 39R12 Vengeance Touring Edition Toy Hauler, with a Can-Am Spyder RT