While I have no doubt that showcasing happens, I also have no doubt that brick and mortar stores are overstating it.

Online retailers often provide better information that brick and mortar stores. The former usually provides free samples of electronic goods and datasheets for physical goods. I've been had sales people get angry at me, and managers threaten me, for asking for the same level of service as online retailers (which is kinda odd because I have a meek personality). Granted, it is much more common for them to tell me to look stuff up online.

If you can get better information about a product online, why would a person ever step into a brick and mortar store? For most products, it is because they want to buy the product now. They step in, find out that the product costs far too much, then they step out. There is nothing wrong with that. Some products may be more susceptible to showcasing, because they are expensive and people want to try them out first. Yet that is no different from the days before the Internet, because people usually comparison shopped for those items.

This comparison shopping was no different because there were mailorder houses. There were even stores with just a service counter and a warehouse (the customer had no access to the warehouse portion, so think of it as retail meets mailorder). So there were expensive places to showroom and cheap places to buy. Businesses used to grumble about this, but I doubt that there were people arguing that you had a moral obligation to buy at the expensive store.

I would argue that the current complaints of brick and mortar stores are nothing more than brainwashing. They are attempting to redefine social values to reflect their interests, even though it is a detriment to our own interests. By the sounds of it, it is rather effective.