That is what I don't get. If you plan on going to the meal when you make a reservation or at least cancel it if you decide not to go, then why would it deter you from making reservations? You would only be charged if your a no-show. Why do you think there would be pushback against it?
Because stuff comes up and plans change at the last minute. With the current CC hold "rules" you must cancel within about a day (or two) in order to not pay the no-show fee. If I get sick the day of a reservation, under those current policies, I'd be charged money. (And since I go solo, there is no "well if part of your party shows up..."). Currently, that's a risk in very limited locations (none of which I happen to be going to on my next trip). If expanded, that risk would outweigh the reward of going there and thus pushing me to spend less money at said locations and eating QS/Off-site for most of my meals.
Now, for certain restaurants, sure, go right ahead. It's appropriate for the seriously in-demand places (Le Cellier, Ohana Dinner, Chef Mickey breakfast, CP Breakfast), but nowhere near appropriate for other locations.
Now, I will say that I intend to use all the reservations I made (or cancel them if I should happen to not use them), but I do not agree with being tied down to them via my wallet.
I'm sure there are many others who would be sketchy about giving out their CC information online or over the phone as well. Granted, we're all going to Disney so chances are we've given it to them once, but limiting exposure to the smallest amount is definitely not bad practice. (Note, I don't particularly feel this way myself, I take precautions when I can and do a lot of online shopping, but I understand why many others would be skittish).
So, to recap. Placing CC holds on "everywhere" is not appropriate and an overreaction. Only a very few (albeit more than currently) really need this sort of reservation restriction. I'd not be opposed to adding several more that are super popular, but adding them all would be going way too far.
ETA:
Also, in regards to the current no-show policy and partial parties. This would cause havoc with the odd-number parties who are very limited unless they grow an invisible infant. Would you really want to see every party of 1,3,5,7,9 charged $20 per meal because that mystery infant didn't show? (Yes, even if the missing person is an infant, they'd be charged the no-show penalty, at least at fixed-price locations right now (CG is a little different)). That right there would drive the amount of reservations down, and the general attitude toward the system much further away than it is.
(One of these days, I'm going to make a restaurant that has all odd number shaped tables, just to stick it to the "man"!... though a table for 1 may be tough since there is no 1 sided polygon, other than a circle, and that doesn't count because I said so)