I don't usually pay attention to dress codes, only because I usually where nice shorts or pants and a collared shirt, even if i'm just going to the range. I'm playing in a scramble tomorrow at a private course, in which they do list a dress code, which is expected and have no issues abiding by, no matter how much I hate tucking in my shirt, can't stand wearing a belt when I golf, don't know why, but just do. Heck they even have a dress code for what you can wear into the clubhouse.
I would posit this, is the game better off catering to those who spend more time/money on the game or those who play a couple times a year?
I would find it surprising if any person who have become long term participants would have any issue with the minimal dress codes most courses have. The issue is this, either side is only going to be able to provide anecdotal evidence which will do nothing to convince the other. Honestly though, I still say the dress codes are neither good nor bad for the game. They are really a non-issue, at least here, because there so many courses that only require shirt/shoes/pants* and your own clubs.