Catholics why must we dress so inappropriately for Mass?

Every Sunday we attend church and Every Sunday the same issue makes my eyes twitch;People dress inappropriately at church. Whenever I go out to dinner with my husband we'll be out and about and you see people dressed so nicely! You see them at restaurants,work,the movies,etc..and they are dressed to impress. But you walk into a Catholic church on a Sunday and the first thing you see are grubby teenagers in their cargo shorts,flip flops and a shirt that has probably never been ironed. Girls are no better,they use skirts and outfits that leave NOTHING to the imagination. I mean really people we're at church!
I have to hand it to the various other churches around town (ie:Baptist,Methodist,Lutheran,etc)as soon as their services are out and you see people walk it they look nice! Men wear Suit and ties and women have their best dresses on,children,teenagers,the old ,the young all dressed to see the King of Kings!
Have we such little respect for our Mass that we need to dress like slobs? This has been egging at me for quite a while now and today I have to say was the breaking point when my son asked me why that man was not wearing "God's Castle Clothes"and dressed like he was at the beach.He also informed me that the man was "naughty" because you always have to wear nice clothes to see "Papa Dios"(God). People this is my 4 year old noticing this. Is there not something wrong when a child can see the problem in this?

I hate to say this but this is an absolute reflection of the degradation of our society. The fact that we put ourselves at the same level as God because we feel that yes we go to church and yes we believe yet he doesn't deserve our very best,he doesn't deserve our complete and total "US". I'm proud of my kids,especially my son who makes an effort to look nice for church. He doesn't understand the Days of the week fully but knows that when we wake up and I tell him we are going to "God's Castle today" he automatically reaches for his clip on tie and "God's Castle shoes" His behavior might not be the best at church but for a child and to the fullest extent of his capacities he knows how important it is to show the King of Kings, Our God,respect..it's a shame adults cant do the same.