I think if someone's concerned about being considered starved and classless simply for eating their whole meal, something's really wrong. This is a problem of social constructs. It might be considered "classless" or something along those lines but what really even is class? 

This is a moral issue on another level too. If we are supposed to dispose of food so that we don't appear "silly", or whatever; what does that say about how we've been trained to treat the rest of the world? There are so many hungry people out there and we're supposed to throw out our food? Even myself; I'm not in any "class",  but I guess you could call me "financially poor as shit". Even so, it is common for me to be expected to throw out food. If you don't like something, you're supposed to throw it out. Not donate it- but throw it out. This is because society doesn't give you any sort of reward for doing good deeds- in fact, when it comes down to it, it usually actually costs you money to donate something. 

It's very hard for me to throw out food because I'm constantly thinking about all the times I've been in such dire need for food and I watch people just waste it on the daily. We are all(ok not all) in bad situations sometimes and I think when we are not it's important to think of those who are.

I guess the reason I'm going on this rant is to say that if you have the money to go to a fine dining establishment and that's where you want to spend it- go for it. That's your choice and I got no problem with that because those employees gotta live too. But, eat your food! Eat every little scrap on the plate and lick it clean. If nothing else, it's a testament to the kitchen staff about how much you liked their food. Whether or not they want to admit it- cooks like to see that. 

And don't be concerned about what other's think. The people that judge you for what you eat are hopeless, lost causes. If they give you a look, give them a goofy smile. Do something silly. Screw em!

Cheers :)