I just thought I'd point out another net positive or reason for Disney instituting this policy.
The CM's who are your Servers at these restaurants. Why I don't know the specifics of Disney's contracts, in general, Servers (aka. waiters/waitresses) get their income via Tips. Their paycheck is only enough to cover taxes/benefits. [Minimum wage is around $7.50/hr now. Servers however are only required to be paid $2.13/hr with the expectation that tip income will bring them above the minimum wage].
So people can (and are) making arguments that no matter what onsite restaurant they eat at, TS or QS, Disney still gets the money.... You cannot say the same about the serving staff at the restaurant you just ditched your ADR at. (and I won't even get into the tip-out'd positions like hostesses, bus boys, bartenders, etc)
Now multiply this by the large anecdotal percentage of no-show ADR's across the resort, and you can easily see there being a good number of servers getting screwed in the deal. And for locations that have particularly bad no-show numbers, you end up having Disney make up the difference between what the server made in tips and the regular federal minimum wage..... assuming the union contracts aren't even more limiting.)
Soooo... You can see this CC guarantee serving multiple purposes.
1. provide Guests with an extra motivation to either go to or cancel their ADR's, instead of just pulling a no-show.
2. Help fill the seats in the restaurants with people either showing up for their ADRs or via Walk-ups..... which helps ensure that the servers working there make their tip $$$.
3. In cases of cancellations, Disney can better forecast needed staffing levels so you don't force employees to sit around twiddling their thumbs all night for no $$$
4. and in cases of no-shows, the $10 fee can help offset the increased labor costs Disney incurred by having staff working that didn't get tips..... ultimately resulting Disney paying several $$ per hr more for the staff than they would've needed to pay otherwise.