I think it's the sentiment that's objectionable. Your employer isn't a feudal lord providing sustenance to you out of noblesse oblige. It's a corporation with whom you have a business relationship - you provide skills and they compensate you for them. If you withdrew your labor from them, the cost of hiring labor increases ever so slightly for them due to the shrinking of the labor pool. It may be an asymmetrical relationship but it's not built on charity in either direction.