I wear flip flops alot. They are swarvoski crystal flip flops that cost me over $100 and go very nicely with dress pants in the warmer weather. Sorry, I would have never dreamed that I was offending anyone and take a lot of pride in my appearance. I get tons of compliments from people and inquires as to where they can purchase my shoes. Not everyone feels the same way and to each their own I suppose.
I'm not the poster, but I'm thinking that the poster probably was talking about those rubber type flip flops that they sell at Old Navy. There's a time and place for those, and I'll agree that a nice restaurant is not the place for it.
I do think people dress more and more casual nowadays. For me, it's fun getting dressed up every now and then and go to a nice restaurant. Although generally, what people wear don't bother me, but for myself, I enjoy getting all jazzed up and going somewhere nicer.
The few times I've bought them for a holiday or to wear on stage they only wore them once and then I had to pass them on! $25 for a pair of shoes to wear only once really bites! But we don't go to anyplace for dinner with a dress code as a family. DS's wouldn't enjoy it at all, (actually neither would DH) and it would be a waste. We only do family/casual places. Fits our lifestyle much better! We go where we feel comfortable in what we're wearing, don't really care (or even have time to notice) what others are wearing. As for specialness, just getting to go out to eat (no cooking or dishes) is special to me! 
And did not have 'real' shoes on.

