The original poster was denigrating all pierced women. The person you replied to merely expressed a preference. Semantically I prefer women who don't have septum or nipple piercings and I'm disappointed so many women have one or the other is the same statement save that it expresses an emotion that the person feels not one he feels THEY should feel. Also its quite possible that more people in his dating pool have this preference than the entire US population because he is liable to encounter and date people in a comparatively small age and culture range on average. I would assume young urban women are more likely to pierce. I think you are more reacting to the negative nature of the parent post rather than the relatively mild statement made by commenter.
michaelmrose
If you had a preference for dark hair and many dark haired women were going blonde you might be disappointed in a general decrease in women who met your ideal aesthetic. If you aren't shallow or are shallow but aren't a beautiful rich Adonis you probably aren't turning down any dates based on such criteria but mathematically trends which run contra to preference mean a decrease in average fitness according to your own accounting.
Imagine if a huge portion of men were really into boy bands and mullets. The trend would mean that if you selected men based on other more meaningful criteria like financial stability and emotional maturity that you have an increasing chance of a mullet in your future. As critical mullet mass approaches you may feel disappointed at the popularity of the trend.
On most phones the end result will look fairly poor AND it will be a pain in the ass.
I do not think you are stupid. I am aware that its not exactly rare for men to be misogynists. I don't think people put as much effort into precise choice of words as you are.