I didn't read the post that you're referring to, Chele11, so I might be totally off target with this...
I'm all for self-teaching where appropriate. I'm all for reading books, watching videos, and learning everything possible about horsemanship through every source available. I very much understand how difficult it can be to budget for training sessions/riding lessons after all of the other expenses of horse ownership (and life in general, in the current economic conditions).
The thing is, and a probable reason why there can be negative comments like you described, is that there are some problems/endeavors that really are best/most safely undertaken with the help of a professional. Jumping is one of those things - the correct saddle fosters the correct position, maximizing stability and safety of horse and rider. Can you jump in a non-jumping saddle? To a degree, but it isn't going to help horse or rider learn proper/safe form. Another place where the same kind of comments crop up is when someone has a major training problem and refuses to search for on-site professional help - some problems simply can't be safely handled by novice riders.
Often, it doesn't need to be a self-proclaimed, shingle-hanging professional. There might be a more knowledgeable horseman locally, a friend or neighbor, who can explain/demonstrate/teach more advanced concepts and techniques, or deal with a training problem.
Could you please post a link to the thread you're referencing, Chele11? I'd be interested to read it (there are a lot of jumping threads to look through
). I expect the majority of the comments truly were made with the best interest of the rider and horse at heart.