It's really funny to me how money keeps being brought up as Disney's motivator. Like it's somehow a revelation no one else has thought about.
Because, duh.
If there are less DAS users unexpectedly going into the LLs, that means Stand-by lines move faster (note, this doesn't necessarily mean they will be shorter, or that instead of 1 hr they will take 40 min, just that the ratio of LL vs Stand-by will be less), and if Stand-by keeps moving instead of having guests stand still for 10 mins because there is suddenly 300 unexpected guests in LL then Stand-by guests are happier, happy guests spend money and book more vacations.
Less DAS guests in the LLs means Disney can control the amount of G+ it sells better. The better Genie+ works the happier Genie+ guests are. Happy guests spend money and book more vacations.
It's not rocket science. Its simply that having less DAS users is better for everyone, including guests who truly need DAS to be able to go to Disney Parks.