Fashion Faux Pas?

I am not what most people would call fashionable.  I don’t follow the fashion world I despise shopping and can never find anything I like.  I’m not a slob by any means and I do care about how I look but I wear what I like and what I think suits me, I pay no heed to what is “in or out”.  I’m sure there must be a semblance of style somewhere in the clothes I wear I’m just not entirely sure what it is.
Working with young kids the majority of my clothes are practical and casual, a pair of tennis shoes, jeans and a short sleeve shirt are my everyday basics.  I don’t tend to wear much if any makeup during the day and the only jewelry I wear regularly are my wedding rings and stud earrings. Although that does have a lot to do with a number of metal and cosmetic allergies I have.  Brings to mind an unfortunate episode with waterproof mascara and several weeks waiting for my eyelashes to grow back. I can only wear certain jewlery none of which is cheap and I don’t need a necklace worth a couple hundred dollars getting ripped off by an overzealous 3 year old. My hair is usually in a ponytail again due to the risk of having it ripped out by an overzealous 3 year old. When I go out however I always change into something a bit better and fix my hair and makeup, in short I make an effort.  To me going out any other way even dressed as I was for work which really isn’t that bad bothers me.
 So what this all boils down to is this; when the heck did sweatpants and a stained tank top become suitable for dinner out?  When I go to a nice restaurant or even a simple sit down restaurant I don’t like seeing someone walk by with the word juicy across their derriere.  It’s not becoming on anyone.  The funny thing I notice about most of the people dressed like this is they are usually girls in their teens and early twenties who also happen to be wearing enough makeup to decorate a herd of elephants. It’s clear by the level of makeup, accessories and the designer handbag draped over their shoulder that they think about how they look. So how in the world does it occur to them to pull a shirt from the hamper and throw on the nearest pair of sweats or god forbid pajama bottoms and go outside in public? 
Now I know fashion changes and I did some strange things as a teen and young adult that can only be described as interesting and even today not everything I wear is mainstream but it has always been clean and appropriate for the activity. To me wearing sweats to dinner out is like wearing jeans to a black tie affair; inappropriate. If sweats are now considered fashionable I’m quite content to be completely out of touch.