I don't understand The Big Bang Theory

I just don't understand the show.  My family watches it religiously so I've been sucked in, but I still catch myself from entering the clan of the devout fans.  I just can't help but realize that none of these people are functioning human beings aside from Leonard and Penny.  Even then...those two characters have such pitiful existences.  Penny is a failing actress who hangs out with people who are so far out of her normal social circle, that she clearly must be SOOOO INDEPENDENT AND QUIRKY.  Leonard is cool though.  He does what he loves, and has normal social anxieties, and an overbearing mother.  He's like me....but with a PhD.

All of these characters are just so socially inept that I feel uncomfortable being around them (except Leonard and Penny).  Howard is just on the verge of being a sexual criminal, Raj is has some sort of mental disease and Sheldon is just a egotisical sociopath.  Sheldon literally does not care about anyone around him...ever.  Not even this cast of people...the only people who love him for whatever reason.  I could understand Leonard wanting to hang around these guys because he grew up with them.  They were his friends for the longest time and so no amount of awkwardness could break their bonds of brotherhood, but that just sucks for Leonard. The one thing I never quite understood was Penny.

Penny is a completely normal, functional, young woman.  Can't she find better friends than these guys and her two "girlfriends" Bernadette and Amy?  These people literally have no social tact and they're so obviously made to be unattractive.  Bernadette is nice but she doesn't get enough time on screen.  I've never known such a hot girl to hang out or sleep with such a crew.  Her ex boyfriends seemed like more fun than this cast.  I just find it highly unrealistic.

Penny...go out and get some better friends and stop sleeping with the faculty of some unknown university.  Broaden your horizons and get some new friends who share common goals and interests so this show can finally make sense. And Leonard...keep doing you.  You're alright by me.  Thanks/