you're absolutely right. When replacing frost proof sillcocks you do have to do a lot of crap on the inside of the house since they go into the house. For me, this time 2 out of 3 of them were in horribly cramped locations and I had to be careful soldering (didn't want to use a shark bite since I don't trust them for long periods of time) or I had to do a bunch of prep work to make sure soldering would go smoothly in such a tight location.
Your friends' that froze, was that a frost proof sillcock as well? Or was it just a regular sillcock/hose bib? If it was a frost proof one, I'm assuming it was due to a bad drain angle or a hose was attached, correct?
And all 3 of the sillcocks I replaced do have shut offs, they just were never used since my parents trusted the frost proof sillcocks from not freezing. I ended up replacing one of the shut offs with a quarter turn ball valve, and the other two I left since they were working (although I should have probably replaced them too since they were so old... probably going to have to replace them in a few years now, lol).