Frankly if you can't see why someone working hard would be annoyed with their money going towards taxes that pay for people to enjoy a life that they are not enjoying, then you are no better than someone saying "Don't be lazy, just get a job". People do different things, some people want to make lots of money or have a 'good' career, and sometimes you have to suffer through the bad side of your choices. A bit of empathy goes a long way.
I don't think the place to aim for is income tax. Tax in the 70s was crazy (the Beatles wrote a pretty famous song about it, it was in the 90%s in the UK). Frankly I don't think income tax should ever be above 50%.
Taxing capital gains on the other hand should be higher than in the 20%s for people "making" millions a year this way. Not to mention how easily corporations dodge tax, or how people can inherit vast fortunes without doing or risking a thing. Aiming at raising income tax is just pointing badly off people against slightly better off people, all whilst the truly wealthy are ignored.