Er, where? Seen that from people I don't know personally maybe like twice.
Many of the ones I went to school with are still young adults with little money to be spending time browsing the internet for things to buy, especially when the good art schools cost a fortune compared to your typical four year colleges/universities. They work their ass off during the school year, in class, and out. Fashion week alone for them is exhausting, and many aren't even presenting something.
What do you consider major designers? Mainstream? Name dropped in every hip hop/r&b song? appealing to both the mens, and women's market? a hot brand in the moment like Rick Owens?
Having a huge influence in the industry? like Marc Jacobs, Raf Simons, Rei, Yohji, McQueen... Iris Van Herpen is in my opinion, a major designer, but she doesn't really fit the bill of the above, and most people don't know jack about her, in school or out.
I find it strange that someone could be in a creative field and not know of their major predecessors and contemporaries. Maybe it's not as important in fashion? Or perhaps most people trying to enter the fashion industry just fail after spending their college bucks.