First of all, it's hard to accept or feel bad about snobbery based on 'mass production,' when what she really meant was 'mass distributed'...because, of course, you are absolutely correct, all sewing machines are mass produced. Their price depends as much on the fact that the chain stores sell thousands of machines every day (maybe a week) where the store will sell one a month. How many people were in your class? Ask them when they bought their machines... they don't run the classes till they have enough people to make up a decent sized class.
There are lovely features on EVERY BRAND of machine out there and I'm assuming that you bought the one you liked and wanted and that had the features you needed. Enjoy your new machine, we are looking forward to seeing some of your new projects.....