To be sure, the only answer seems to have focused on some particular issues that some might consider "engineering", but what was actually asked was a general question about the attenuation of electromagnetic waves in insulators, i.e. dielectrics. This is a topic covered in a myriad of courses and texts on classical electromagnetism taught and written by physicists. Should any question on index of refraction also be rejected as engineering, since it is also a concept used by engineers and involves electromagnetic waves in dielectric media?
The change to require only three close votes for a question to be closed has been very effective at closing the more outrageous homework questions rapidly, but it is also causing a small but significant number of questions to be closed inappropriately. Recently I have found myself voting to leave open or reopen almost as often as I vote to close when reviewing the queues.
I still think the change is worthwhile and shouldn't be reversed, but it does mean the onus is upon us to think before we close vote. I would urge everyone to consider carefully when deciding if a question really deserves the nuclear option.
It's a symptom of trouble in academic physics: the drive to abstract mathematical formulation at the expense of practical, real-world science. What's our biggest problem in physics these days? I think it's what Sadler's social experiment revealed.