In the salon, there are some things that women talk about, and they start to really hang their heads and look embarrassed. One might think that they would be talking about something scandalous, like a clandestine affair...but no. They always do this while talking about washing hair every day, as if they have committed a true crime.
For sure, there are far worse things than washing hair everyday. I think it may have developed such a bad reputation simply because when someone is washing their hair everyday, they may be doing a great deal of aggressive heat styling every day as well.
Like just about every other bit of beauty in the world, it depends. If your hair is dry, requires a blow dry that takes 45 minutes to an hour, and you need to use the flat iron to really get it smooth and under control (I hope you don't though....) you may want to wash your hair every other day, or even every third day. This way you can really set aside the proper amount of time the day that you do wash your hair, and save yourself lots of time (and heat styling) the other days.
If you have fine, light blonde hair, you may need to wash your hair every single day if you'd like it to look it's best. I've personally never been a fan of dry shampoo. I think it's better in a pinch than having visible flat, hair that needs to be washed, but I question how healthy it really is for one's scalp. I'd rather see someone shampoo their hair daily with a gentle, high quality shampoo, than to coat their scalp with a dry shampoo, possible damaging the hair follicles in the process.
If you go to the gym daily, work in a job where you feel you need to wash your hair upon arriving home, or just feel better about yourself when you wash your hair each and every day....be my guest. As long as you use a high quality shampoo, apply a heat protectant and style your hair gently (avoiding the flat iron) your hair should remain healthy and beautiful.
Stay healthy and beautiful!