Why would some blue collar people hold a grudge against someone because they may not work as hard as they do?

I've witnessed this before. You have a guy who has grown up with things that some blue collar workers never have had the opportunity to have. No matter how nice the person's personality is , these blue collar workers just never will like this person. The person they don't like works in an air conditioned office all day long while the blue collar workers are up in the air all day building stuff. The blue collar workers work in the cold and the heat. The guy that works in the office sits at a desk all day long and has a white collar job that he was born into and I don't blame that guy for working in the office, but man he gets treated like **** by these blue collar workers. These blue collar workers would be working the same job in the office as this guy if they were given the opportunity to have it, so why in the world would they hold this against a person who has that job? I don't understand it.