There are a few other threads as well, particularly about Swat and KKH. People just want to go to places with pleasant weather during summer.
For Swat, the question asked is the security situation.
For KKH, the question asked is the condition its in and how long it takes from RWP/ISB to Gilgit, which used to be 14 to 16 hours two years ago and last year it maxed out at 24 to 25 hours. An overnight stay at Besham or Dasu or Chilas is not what most people are looking for. Plus, in 2009 and 2010 a lot of bikers and others canceled their trips to northern areas because Babusar pass was not opened for traffic in time. A lot of people want to avoid KKH as far as possible and Babusar pass is the only alternative, taking them directly beyond Chilas.
Nathiagali is a one day stop. Patriata, Bhurban, Ayubia/Khanaspur and Nathiagali two or three days max.
So, Kaghan is the only option left for MOST people.