I like ARFs and I like kits. I have built a TF P-47 and in the process of building a SkySharkRC Tempest. I only buy ARFs for one reason.

1: I like to fly 3d Planes/aerobatic planes.
Now I am not going to build a 3d plane or an aerobatic plane kit and crash it while doing aerobatics. I would feel 10X more horrible if I crashed a kit than an ARF. So I buy aerobatic ARFs.

The only kits that I build are of warbirds. Mainly because I can build/modify them the way I want to and they look a lot more scale than some of the ARFs out there.
It is tough modifying an ARF except after you crash it. Only then you can make it stronger in its weak areas.