Yeas, a lot of people use the camera body size as parameter, and this is silly because the camera size doesn't tell anything at all about it's quality. It doesn't even tell if it is developed or appropriated for professional use or not.
Here is a hilarious story from Jason Chambers, telling how a police officer assumed Jason was doing professional work in the park just because of the size of his camera:
Bigger is better (PRO) happened to me yesterday.
I’m sitting in our local park with my gripped D300, SB700 Speedlight, and a Nikor 16-35mm f/4 when a police man asks me if I have a permit from the city to be doing professional photography in the park. I tell him I’m not doing professional photographer in the park, I’m not doing any photography in the park, I’m just sitting. “Why do you have that camera?” “Just in case something catches my eye.” “Well, you need a permit.” Now, there is another guy in the park taking pictures. He has a Nikon D800e and a Nikor 24mm f/1.4 and I ask if that guy has a permit. The police man says no, he doesn’t need one because he isn’t a professional photographer. I try telling the officer that that guy has three times the megapixels I have, a lens that cost twice as much as mine, and his camera is at least five years newer and much more expensive than mine. And the answer I get is….
“Yes, but yours is bigger”
I guess no matter how good the D800e is, mine goes to 11.
On the photographer point of view there are also the good client and the bad client. The bad client is the one who who makes you spend money on what you don't actually need just to convince them you are a good professional, doesn't matter how impressive is the photographer's portfolio. On the other hands they are easy to be fooled by bad professionals.
The good client is the one who says "it doesn't matter how you do it, as far you do it like I saw in your portfolio". The confident client who knows what they want.