Well, I can think of serveral reasons not to sell expensive gear via online shopping/mail order to individuals: Due to german laws, any supplier is required to take back any order without given reason within 14 days. So it is not uncommon that people order expensive stuff like cameras, go to vacation and return the stuff in time- so the seller has lots of hassle doing the return and can sell the gear only for reduced price to the next buyer.
Some shops that do photographic gear list the expensive cameras in their shop, but claim that first-time-buyers need some personal demonstration in the store before buying to protect against this kind of customers.
But this would only explain why gear above some magic mark would be affected, maybe the oscilloscopes and bench DMMs etc.- the handheld DMMs are quite cheap compared to the rest...
Or lots of untrained wannabes create lots of hassle within support, so they try to cut them off...