I see a couple problems here.
First, the salesman should have done a proper Manual J and D. No question about it. the home owner is partially to blame. Ya thats right. If you as a HO'r don't want to educate yourself or you would rather continually repair an obviously bad install, then stop complaining and definitely don't blame a manufacture.
Two: as someone already said (Udarrell, i think) serious red flag should go up when they tech couldn't wire a thermostat correctly. The Stat and the HP come with wiring diagrams, seriously read the instructions, it ain't that hard
Three: I leave "educating the consumer" to the salesman. THATS THEIR JOB. (actually MY job ) As they say "Education starts in the home". The education continues AFTER the install is complete and you get paid. Insist on showing the consumer what they just invested in. SHOW them how the thing works. It may go in one ear and out the other, but educate them anyway. Show them what to look for, show them how the machine is suppose to sound and act. Show them any diagnostic lights they should look for if there is a problem.