It's not about booking... and especially since the episode u used as an example was from May '99, because Russo and Ferrara were getting away with some wack shyt by then.
It's about how cool wrestling is at the time. Simple as that. It had reached a certain level of popularity and it brought on a lot of casual fans AND bandwagon fans. There are people right now who don't watch wrestling no matter how good or bad the booking is, but 14 years ago watched Al Snow and Bossman feuding because Bossman cooked Snow's dog.
If something happens that makes wrestling the "in thing" to watch again, similar ratings will come. But it won't have to do with booking, it'll have to do with a particular group of stars or an overall presentation that restores that "boom period" level of viewership. When you have that, the writers can pretty much book whatever they want and people will watch because "OMG wrestling iz kool".