I would say it could be considered unfortunate that the approach to the question could have been different and gotten the desired results. If instead the question had been: I've been using product x (something else), and am considering using Zen Cart, could someone explain the benefits to help make an informed decision? Maybe someone that has previously used that product can explain why they no longer do, or why they chose to use Zen Cart inthe situation(s) they did?
If the question(s) were asked in that way, maybe we wouldn't be talking about the way that it was being asked and whether it was tasteful to ask. That said, and I certainly am not attempting to instigate anything, I can see huge value in Zen Cart the program and the open source aspect of it. Our group came to use this because another non-profit does and one of our volunteers pointed us in this direction. Free software that permits the opportunity to raise money. First, what could be better than that. Next the adaptability of it, don't like something, change it. Don't like the look, get a plugin, redesign it, "worst case" hire someone to give the look that is desired if unable to do on ones own. Want to find the code or area that is presenting something on screen, use the built in tool that tells you which file and what line it is on. So. Much is there that, personally what more could one ask for. Have we used something else, no, so there is a bit of bias there, but have we found that there is something wrong with what we have available? No. Is the product going towards maybe "looking" better? Absolutely, 1.6.0 is headed in that direction or at least making it more adaptable to provide visual "improvements".
I would though say that it is a fair approach to "speak" with those that live it in addition to the advertising and writeups by others. It's only an opportunity to gain a balanced perspective. Personally though, may consider some way to live it, breath it, sample it by reaching out to the "desired" product team and see if they would entertain that idea for a short time possibly on a development server to see if it is worth investing fully. In essence do some "non-intrusive" research. Visit the help center of the product to get an idea of how things work, etc... But whatever the case, may want to try to determine what it is that seems to be missing or missing the mark and see what it would take to get where desired. May not be the product, but the approach taken to use it.
Just my two cents worth.