What Am I Doing Wrong?

I have been seeing pins on Pinterest about this, and people talking on facebook about it, etc.  Apparently for some people it is hard for them to wash a sweater. Like they never wash their sweaters. I am honestly confused.  Am I doing something wrong?????  Is there something I should know??  Why can't a person wash a sweater?  I always wash my sweaters.  I love sweaters. I wear the heck out of them.  They don't seem ruined when they come out of the dryer?  Are they?  I wash them on delicate (whether or not they say hand wash or dry clean or whatever) and then dry them on low heat or no heat depending on the sweater thickness.  Usually on the dry clean only I will go the extra mile and lay it out to dry after it has been washed.  hehe!  I don't understand....hhmmmmmm...