I don't look at it as spending $25 for FOOD--I see it as $25 for food AND ENTERTAINMENT.
I really didn't choose any of the character meals we did (and will do) for the food--but for the characters and the atmosphere. I figure I am spending about $10-15 for a (hopefully) decent meal and the rest is for my children being able to see 5 or so of their favorite characters and get autographs and photos with them in a semi-relaxed setting--air conditioning, sitting down to wait, easy access to pottys, all the food they want--NO LINES!
It is worth the extra money to be able to get their character fix in that sort of atmosphere rather than standing in line for an hour or more in the heat on the HOPE that the ones they want will be there, or they won't go on break before your turn. Yes, no characters are "guaranteed" at a Char. Meal, but we have a fairly good general idea of who to expect and have never been disappointed. This also allows us to spend our park time on the rides and such, and not waiting for Mickey etc...
I also really like buffets because I am not a really adventerous eater, but do like to try new and different things occasionally. I like being able to just try a taste of this and that and get more if I like it. I also like that my picky eaters can get a little of this and that and be happy. And they can try all they want from the "adult" area and not be stuck with chicken fingers and mac and cheese as the only options at the child's price. And as others said--having a meal that includes fruit and veggies included is worth it.
And of course, you can't beat being able to sample one of every dessert!!!! (and more of the ones you really like!)
If you look at the cost of your local Dinner Theatre, or the cost of dinner out and a movie (even at the local Golden Corral or other buffet type place) it is really comparable. Food and Entertainment. And you don't bring your camera to those and catch that once in a lifetime smile on your little (or big!) one's faces as they hug their favorite character.
Priceless!