If we were all as lucky as Genghis, then we could just wear a nomex flight suit and not have to worry so much about ironing, neck ring collar (the a cut above shirt have a special neck comfort system that prevents neck ring), and our clothes fusing to our skin. Actually, a friend of mine asked me why we all didnīt just wear flight suits for flight training and aerial work, which is a good question I think, for the obvious safety reasons
I don't think that buying a second hand Nomex suit on eBay is a particular issue of luck. And this is a private flying page, and anybody paying for their own flying can surely wear anything that they jolly well like.
The only time I ever had to fly in a uniform, it was green (and fire retardant) - so not an issue. If I had to fly in a civvie uniform, sod it, I'll pay for some decent cotton trousers & shirts and woollen jumpers. Unlikely to cost much different to a couple of pairs of jeans and a new shirt and jumper anyhow. It's simply a matter of being selective. If you can't get them here, several Indian/Thai/Polish tailors have websites and will make to measure for sensible prices.
I think that your friend is right, we should wear appropriate clothing. I don't think that luck is an issue - if you fly military aircraft professionally the clothing will be safe enough, if you fly civil aircraft in an environment that requires a uniform, there are plenty of people who will sell you natural fibre equivalents. If you pay for your own flying, you can wear what you like - M&S cotton chinos and Cotton Traders cotton polo-necks work fine for me.
And ironing your shirts is surely just a matter of personal standards - I do that anyhow for non-flying clothing!
G