He is not exactly wrong.
There are certain areas of the Pashtun belt they completely struggle to penetrate because there is absolutely minimal sympathies from the locals there, and many times led to counter violence against them by local tribal elders.
Other areas for several reasons do indeed harbour sympathies on ethnic, tribal or ideological grounds (their extremism is appealing) so they find it easier to sustain their presence, blend in, go unnoticed, get zero push back. Or at best neutrality.
The fear factor you mentioned is certainly true in many cases, but overplayed, tribals have never shied away from using violence against those they deem disturbing their areas and a simple fact an insurgency of this intensity simply cannot sustain itself without finding local allies. It rapidly dies out once existing militants are killed, struggling to gain recruitment or ability to operate in any area without risk of being found out.
It may be new to some, but TTPs ethnic composition and extremist policies are certainly appealing to many. Just a fact. This is the biggest contributor over fear. Fear is about 20%. 60% local sympathies, 20% remaining Afghan susstainment & infiltration.
Now with BLA? 85-90% is local support. 10% came from camps that over the year shifted at times between Iran and Afghanistan.