More than a few people believe that contactless card (and passport) details are vulnerable to theft by persons using high powered chip readers. Hence the market for special wallets, just search "rfid blocking wallets".
At least in America, I find that people don't even notice the logo or know what it means.
Once again, everyone else has to suffer because there's a few nutty people out there.
I could try that. Assuming the mastercard logo is also on the back, that may solve the problem. Still - if I must hand the card with the back showing so they can see the wifi symbol... why place it there? I mean if the symbol is pertinent info for the waitstaff and/or counter staff, why hide it? Ridiculous imo.
I bet the waiter flips the card over the "correct" way once you hand the card to them.