This is a more bigoted view than anything Trump has said.
Hillary supporters: "If you don't vote for Hillary in the general then you are an idiot. You are young and clueless. You're ignorant. You're racist. You don't care about America. You know nothing about politics."
Have you considered the possibility that some people just plain don't like her?
Um, wow. Yeah, being called ignorant and privileged and having your feelings hurt is just as bigoted and damaging as Trump calling Mexicans rapists and murderers, threatening to deport immigrants' family members, and coyly dancing around denouncing the KKK, a hate group which has viciously murdered black people!
You've pretty much reinforced that poster's point about privilege - to you, "bigotry" is about hurt feelings for being called stupid. There are groups in the US for whom "bigotry" means literally being shot in the street for walking home by themselves or doing nothing at all.
And you're free to not like Hillary (or Sanders, or any other candidate). But to be able to "waste" a vote IS a privilege, a privilege some groups such as women and blacks have had to fight and sometimes die for, and a right that many people in the world still don't have access to. So yeah, you're free to do as you see fit with your vote - including not making one - but you should also recognize the inherent privilege in being able to make that choice in the first place.
It is NOT about privilege. It is not. Millennials are the first generation of Americans that will do worse than their parents in a very long time. They are DROWNING in student debt. The jobs are not paying enough. They cant buy houses. They cant have kids without it ruining their lives. Blue collar Democrats are in a similar position. Underemployed, no careers. All the wealth going upward.
I don't disagree with you, but I think the poster's point about "privilege" wasn't to say "millenials are a privileged group who are well off", but to say, "people don't recognize their own privilege when they say they're going to make a protest vote to make a point, because the reality is they're probably still going to be fairly okay compared to the rest of the world, while for others the consequences are far too real and terrifying to ever "waste" a vote that way."
And if people don't vote because they want to "send a message", honestly the only message most former Bernie supporters will send is "young liberals aren't reliable voters", which is the exact same message they've sent in every past election, and only reinforces the status quo that their voices won't be taken seriously.