Why can't they just emulate a server and play it anyways? They did that for things like .hack//fragment and battlefield 2142, both games from the mid 2000's. The crux of his argument was already covered by one of the more recent Library of Congress rulings IIRC.
If you actually watched Ross' "GaaS is fraud" video you wouldn't be asking this. He was very very clear and presented a counterargument to every argument, including this one.
But here's a good example: Need for Speed World. I played that game when it was still around, and even paid EA to get the diamond finding car because I was a dumb kid with way too much cash on my SIM card, and I lost it all, and didn't knew about the tools you could use to pull your profile before the servers shut down for good.
The game was dead for quite some time, and only got resurrected because the community created server emulators. Big emphasis on "community created", it took a ton of reverse engineering effort to make that happen because the server code was never public. It's not an excuse and Ross was very clear about it in his video.
Here, let me timestamp it for you so your lazy ass won't have to look for it, he nicely explained it with visual aid.
So no, it's not a reasonable copout it's a herculean effort to do server emulation when you don't have access to the source code, or even the binaries for the software that the company used to run the game, and sometimes it's just impossible. NFS:W got lucky, perhaps because it wasn't too technologically advanced since it was based on code from the early 2000's, so the reverse engineering job wasn't hard to do.
Ideally, if the company shuts the server down, they'd release the software so that people can resurrect it. But there is no legal incentive to do so, and corporations have the Dog In The Manger mentality. They don't sell the game, they don't make a profit on it, the code is old and completely useless to them, but they'll never release it because it's their IP, their property, and maybe one day it'll make money, even though this one bit would never make them money ever again, but the C-class executives don't understand that.