I encountered something similar a few years ago. I was looking for a light that I could attach to my Brother CS-6000i. The woman in the store asked me what machine I had and when I told her she stuck her nose in the air and said they didn't carry anything that would work for a "Brother". I won't tell you what I thought about her attitude.
Last year I bought a Janome 7700 because I wanted the larger harp area and it is a lovely machine - but I still love that little Brother and it isn't going anywhere - except to classes because it is very portable and the Janome is NOT.
I did pay for a basic quilting class at my LQS (BTW it was my LQS that recommended the Brother as a good 'starter' machine) and I've taken a couple of other classes there as well. I have no problem paying for classes - I think that is only fair - but as someone else mentioned here there is a ton of information on line and I've learned a lot that way, too.
Anyway, if your machine does what you want and need then that's all that is required. Find someone that will respect what you do and not be critical of the tools you use.