I was told this about not using teflon tape back in the late 70's or early 80's. What I heard was pretty vague, and I dont recall who said it anymore. Anyhow, these days we have better access to information. Either way, I guess I was told correctly to NOT use it, but for the wrong reason. What you said makes a lot of sense. I am fully aware of using teflon tape on plumbing, and when I'd first turn on the water, the faucet strainers would clog. I'd remove them, and find rust particles (if ther was OLD steel pipe involved), -AND- pieces of teflon tape, along with little bits of solder (on copper pipe). On plbg its easy to remove, but I could see orfices and stuff getting quickly clogged on gas pipes.
I'll just stick with using pipe dope on all gas pipes!