I can't imagine that somehow.
Yes, it is some sort of psychobiological issue. Hard for me to grasp as well but it does not change the facts, better to keep smaller but reputable means of payment than many, sometimes unknown methods. This seem quite reasonable.
I got a feeling it may also have something to do with recognition and "advertisement" of other coins.
Let say that I'm a fanboy of coin A and coin B is my "nemesis". I want to buy some sweet deer-jerky, I'm all set, ready to click check out and then... nemesis!
-ooo no, im out of here dude Second scenario could be the unintentional advertisement of a coin. Im doing my shopping and at the checkout I encounter a new coin, that was unknown for me up to this point. I'm interested, intrigued, I will check and research this new coin, some stats, some forum, coin market cap and voila, an hour has passed without the actual transaction. IMO bad thing for businesses, distraction and new perspectives may discourage from buying.
Thats just my uneducated guess on the matter, it may be totally wrong
As to bulk buying mentioned before, now its also looks OK, might have been an issue with page zoom as I was browsing in 125% enlargement, fonts got distorted(?).