To me not so much a debate about traveling with trekking poles, but instead a matter of convenience as to how one approaches it.
I take a couple of things into consideration:
1. Walking the Camino is not a technical hike and expensive high-tech trekking poles, while nice are not a necessity. As I said on here before, you could cut two wooden broomsticks to a proper length and they would work quite well.
2. Purchasing a pair of trekking poles is quite easy and inexpensive when you arrive in say, SJPdP (you can also purchase them in several other towns/cities along the Frances, which I am using as an example because it is the one most discussed on here).
I say inexpensive (about 20-25 euros a pair for the cheaper ones) because let's say someone spent 1000 euros for roundtrip airfare, 150 euros on a backpack, 100 euros on shoes/boots, 100 euros on a sleeping bag, 200 euros on clothing, and so on. When you consider all that, spending say 25 euros on a pair of trekking poles upon arrival is cheap piece of mind knowing there's no chance of delays or hassles when trying to travel (for some a trip of a lifetime) with trekking poles on a carry-on on the way to walk the Camino (which is the best way to transport your backpack IMO). Same goes with anything questionable (liquids etc) in your carry-on backpack.
It is a bit liberating being able just to walk through security, onto the airplane on onwards with all your stuff with you. No worries, no hassles. The only way to travel IMO.