Mostly to avoid scraping. If I was trying to direct people to my website and make it stand out, why would I let others crib my data?
It's always a downhill battle, but the people who implement it know this. They don't care if you've found a new workaround, they've probably got 2 more mitigations ready for the moment you think you've pulled one over on them. The ultimate goal is to tire you out as a developer and make you give up. Judging by the amount of frustration I see online, it sounds like "they" are winning.