It is okay (and good!) to criticize power but there has to be a good reason other than resentment, otherwise you just fall into the trap of sounding like a bitter guy who lost at life and has nothing better to do than to externalize his failure at the current status quo.

I grew up in a former communist country. There, if you were a critical thinker with a strong personality striving for your own economic well-being, you would generally end up labeled as the enemy of the state. The modern capitalist economy tends to reward such people, yet some still feel resentment (hint: in any system, egalitarian or not, there will be those who feel resentment).