No, you see, the idea is that people are happy if the visit 9 (or 10 or whatever the magic number is) attractions within a day. Thanks to MM+ people will be distributed more evenly among the exisiting attractions (that's the efficiency increase), so there is no need to have more attractions available.
Somehow, the people who came up with this train of thought totally forgot that people want to experience attractions that they enjoy and there comes personal taste and expectation in play. There will always be attractions where people come out and think that this was a waste of their time (like me after the Country Bears) or think ok, that was nice but really not that great (like me after Little Mermaid). If you fill up a day of 9 attractions with only these type of experiences, I am pretty sure these people will not think they got good value for their ticket. So you need to provide lots of different attractions for different tastes. But once you start viewing your guests as inventory, you have forgotten what is to be a good host, I guess.