It’s to prevent debris and floaters when you skim. It’s not about being stuck in old ways it’s about production and high end workmanship that dOesnt need a ton of filling afterwards. Scraping a joint might work on small patches. Try that on a whole townhouse complex and watch yourself get kicked off site. Plus….I’m only 51. That’s not old. I’m still learning all the time And I’m the first one to do something new…if it makes sense.