I've never really had that problem, more often, it's that they try to help me too much by offering rides ect. when not needed. I never tell them why it is important to me. I never think to.
Your friends are obivously scared but jealous or they wouldn't find themselves snubbed. But perhaps they take the very reasons that you state as negating what they do. As far as preachy, I never bring up the subject of my bicycling. I answer questions if asked, but to me it's just a non issue.
But I have always been this way, and for many years car free, and sometimes not. I make my strong statements by cycling. I learned in my youth that most people didn't care to follow my path, but that didn't invalidate my taking it.