No need to keep your "trap" shut. Everyone is entitled to an opinion. The way your email was written it was implied that since you have 17 years experience you know it all because of your "level" of experience......almost like you were sticking your chest out trying to make yourself look good. Maybe next time try and word your post so as to no imply that you know everything.
Also, this has not yet turned into an argument. This is a discussion with different opinions. There is a difference.