Makeup

I live in a city that is in constant spring and summer. We get maybe a week of cold. That being said..I don't understand how women can wear so much makeup when you have 100+ weather with 60+ humidity. I understand wanting to be a professional; but do you really need to layer your skin with so much crap? I do wear makeup on days my skin looks blotchy..i put on a little pit of pressed powder, mascara, and a light color of glazeware (avon); every now and then i will put on eyeshadow. I don't get women who put on concealer, foundation, powder, blush, eyeshadow (like 3 coats), masacara, lip liner, lipstick, and lip gloss. C'mon now. Is there really a need for all that? When you step out into the heat/humidity, your face is gonna melt off. Really. So why bother? Keep it light and simple. Maybe someone can help me understand this. When I see women out, and they are sweating, to me I think its gross to see the makeup sweating off their face. Talk about gross. Oh, and another thing...what's up with wearing makeup to go swimming or to go work out in? Working out on your lunch break is one thing or coming off work I understand. But to put makeup on to go to the gym? Or to go to the pool and sit in the sun? Someone help me understand that one please.