It kinda does though. The ISS orbits every 90 minutes or so. Meaning it cycles from very-hot to very-cold.
Doing that for 180 days means thousands of cycles. While not as violent as take-off and landing, it's a factor that can lead to metal fatigue and so on.
Quite how big a factor remains to be seen, hence the fairly strong observance, and testing of parts (earthside) after they return.
If that's what's important then the ISS itself has beaten it. So it still seems like an arbitrarily narrowly chosen record just to make it seem special by limiting it to transport spacecraft. Everything beats some sort of record if you exclude enough others.
I wonder if a deployable sunshade would help extending their life. When Skylab lost one solar panel array on launch, they had to cover it with a blanket to help manage temperatures.
Doing that for 180 days means thousands of cycles. While not as violent as take-off and landing, it's a factor that can lead to metal fatigue and so on.
Quite how big a factor remains to be seen, hence the fairly strong observance, and testing of parts (earthside) after they return.