Instead of emailing, why not pick up the phone and call? Find out when the manager is in and go in, in person, and talk to them I find that if you have a polite conversation (instead of being a faceless email) with a real person - if they care about thier business - they will listen. They may not change anything, but it's more effective than sending an email that may or may not get read out into the ether.
I had a similar experience not too long ago at a shop that I frequent. I was looking for flat shoes like a 5-10 and flat pedals. The just under 30- young man was pretty insistent on "why do you want to get rid of your clips". I've probably been biking since he was in kindergarten. I took the manager aside and told them that I thought it was inappropriate for this young man to say this... especially when I am a known mtb rider in the area. Being one on one with the manager (and later, the owner) made me feel listened to, and hopefully they did something about it. Way better than faceless input, I'm sure.
2015 Liv Intrigue 2
Pro Mongoose Titanium Singlespeed
2012 Trek Madone 4.6 Compact SRAM