If someone else gets it, why shouldn't you?
Those that think in this way, while you think would be in majority when entering the workplace, are in fact a dying breed. Why is this? How can so many people even think that they should have what others have, let alone voice this in the workplace? There have been many occassions I have heard the words 'Well if [insert name here] gets what they want, then I should get what I want!'
Imagine that, a whole world where everyone gets what they want...
Fundamentally I find it difficult to imagine, once you are aware of the realism of the world you start to unpick the logic of why it is the way it is and end up with multiple reasons why it couldn't possibly operate in that way. For every winner, there is also inevitably a loser either directly or indirectly. This is particularly the case in business and the work environment as the very nature of capitalism is to compete.
It's all too easy to take the path of least resistance and speak up about not getting something that someone else has e.g. a promotion, company car, salary increase etc. But if you don't try and keep up with the neighbours, and instead focus on what you are doing. Making sure that you are brought to peoples attention for the work you deliver or the results you achieve rather than complaining. If you can do that better than everybody else, then those people will be wanting the things you have, not the other way round