DSLR cameras vs. Club/Bar/Restaurant policies

Something i noticed in London and on French Riviera staff in let's say "hype" places is openely reluctant to let you go in with a DSLR camera, and i realised bigger it is scarrier it seems. In several places in London i had to convince them to keep it with me instead of leaving it at the cloakroom (managed in 20% of the cases). On french riviera it was a short and sweet no-no. Even in places like bars & restaurants the policy is similar.

Can anybody explain me what is the fuss here? And how to avoid that?

 

At the second paragraph, i completely don't care about the other peoples and socialites, i even must say that at some point their presence is hard to stand in venues/restaurants cf. their rudeness and complete lack of behavior.
I love taking pictures for my own sake of my own friends in places i go to. Point and shoot camera is a big no when you know what you can do with a DSLR, plus i love "situational" pictures.
If smaller cameras are allowed i still don't understand why a big one isn't.

To clarify, in my case a DSLR wasn't itself a problem to get into the venue, but the next stage was (cloakroom recommendation).
Also truth is, i achieved to get through inside with it when the table was at my name or if it was obvious there was some $ involved in my coming to the place.
I think the moment it annoyed me the most it was at Windows bar/restaurant at Hilton Park Lane in London. The view over London there is just amazing and i was with a gorgeous ukrainian girl for a date there. Wanted to take some pictures at high iso long exposure without flash of her and of the view.

 

Let's continue, i was at the Frieze art fair in Regent's Park London, same story "sorry no big cameras". I ultimately managed to get in with the camera anyways by putting it in my friends bag and trying another gate. Thought it has to do with press accreditation or something but i was surprised normal people were also inside with pretty heavy cameras (D3, 5D MkII etc).

Something else i noticed i do scare people off with the camera if i just walk on the street with it. I don't look like a tourist per se plus tourists generally handle D40's or XTi's when it comes to DSLRs and i don't look like a photographer either (i don't walk around with camera gear, only the camera plus an appropriate lens) so people don't get it and get scared, overall if i pass next to them, not taking a picture, generally scared of the fact the camera is so big, like it was a gun or something. Frankly I don't get it.