I get the theory behind it. Better dressed kids at my kids school generally have better dressed parents and vice versa, I remember one day at drop off there was a mom who looked like she was coming from her job at a local gentlemens club and since it's a k-8 school there were some googgly eyed 8th graders and dads. And we have the dads with underwear showing or wearing tshirts with foul language on it. And of course the pj thing. But on the other hand as a mom who knows how stressful the morning routine can be there have been days if I'm not working and coming right home it's grab what's closest and get out the door especially on days I'm home with a sick kid trying to get the other to school or being sick myself.
Think they have a good point about wanting parents to set a good example of how you should dress in school but if you aren't actually going into the school we all have bad mornings. I may grab those sweats or pjs for morning drop off but would never for a parent night, confrence or if I'm volunteering. But then again could see the school turning parents away and losing that home school connection that is so important.
I was amused by one of the responses "no one tells me what to wear" I'm assuming that responder doesn't have a job or wos from home or is self employed because every company I worked for had a dress code.