Courtesy is one of the most important things when it comes to the martial arts. Even if I don't agree with a certain style's training methods, or even if I don't like a particular instructor from another school, each of the above does have its merits, for the most part.
I won't bash another style, their schools, or the instructors (with a couple of exceptions, such as everyone's favorite neo-ninja with the initials of
A.K."). If people want to train in the other schools' methods, and if they don't like what I teach, then that's their right to simply leave, and go train elsewhere.
The way I see it, different styles, different instructors, and different schools, all have something to offer. If they can offer something that is good for the students, then it's not my place to bash them. As long as the other schools conduct themselves in a decent manner, and don't interfere with our operations, then I'll simply have a healthy respect for them.
Now, the question remains, do I have disdain for other schools? Of course. There are many schools that I do not like. Either their instructors are nothing more than glorified thugs, their instruction is sub-par, etc., but I honestly believe that it's up to the prospective student to figure that out for themselves. Maybe that's what they want, or maybe not, but again, it's not my business to spread rumors.
All I can do is teach what I teach, and if people like what they're learning, they'll stick around. Plain and simple.