The problem is and always has been,we love the camera system we are using,and we take it badly when anyone may make the slightest remark otherwise.
For me it up to any person pro or otherwise to use any cameras he pleases.
Now for me a pro is simple,it your job you wake up everyday and do that job,it paid the bills and keep you alive,and you use the best camera for the job,and for me when i was it meant i might be using an large format camera one day the next an SLR it was the films days.
And at the end of the day a photo is an product when you are a pro, and as i have said you use the best gear you can to turn out that product.