Just send him a link to this site and let him poke around.
Why don't you invite him along and prove him wrong! Make a good stalk, stick a pig, and recover it.
Guys are set in there ways when it comes to the whole compound or nothing thing. My buddy has an even stranger mentality I couldn't explain well.
That email doesn't bother me nearly as much as a TRAD only guy in my bowhunter ed course that insisted you can never sharpen a broadhead as sharp as factory once it's been shot. OK, lemme show you what my arm looked like after a day witht he KME...