As someone who is VERY new to bonsai, I can say that my mallsai tree is what inspired me to actually look into raising an actual bonsai tree. While I think it is very sad that such an ancient, beautiful art is undermined in the way it is, I do think that mallsai does encourage people to look into actually getting a bonsai.
How many people post on this form looking for care help with their tree, fully ready to care for a real bonsai, and then end up disappointed and go out and look for a tree that can some day become the real thing? I think it's important that people who get sucked into the mallsai scam, much like myself, are encouraged rather than frowned upon. My mallsai was a five dollar clearance impulse purchase, but I am now in the process of raising another tree. If we want the art of bonsai to grow, we should give mallsai purchasers hope that their tree does have at least the smallest amount of potential, and encourage them to go out and look into a better tree! While this is an unfortunate situation, out of all the forums I've been on looking for advice, I feel overall that we aren't making the best of it.
That being said, I can completely understand being bitter. Just, try not to take that bitterness out on the inexperienced buyer.