Well, you are right.

The thing is, the definition of "good by my standard" that I'm applying here is quite a basic one: what impacts people positively, without impacting other people negatively. It doesn't work for the most grey or ambiguous areas, but as a default baseline it works fine I would say.

So Hitler wasn't having "good" intentions because his intentions were to impact people negatively.

Obviously, if you start digging deeper, this core standard requires additional rules and such. Fighting against rich people would be bad according to this core, but I don't believe that it is bad; the reason for that is that rich people decide to be rich, and have a negative impact that is too important to neglect. Taxing them would then be good, because it helps people who are living poorer than they should be, by taking from people who are richer than they should be -> this adds a rule/exception of equity and of treating "bad" people under different rules (if you initiate something bad, then you stop counting as much in the balance of things, which varies depending on what you did).

And yeah, this all ends up pretty subjectively, but I don't think that there is such a thing as an objective definition of good and evil, it depends on the scope. The scope that I'm trying to have is one that leads (or so I believe) to a fair and harmonious society, where people don't suffer (or as little as possible). Then you can even nitpick that wanting a fair society is also a subjective opinion (typically, capitalism wants the opposite, since the concept is to advantage some people by disadvantaging others), but there will never be a 100% consensus. Sometimes subjectivity is unavoidable, but I think that generally, decent people will at least have the idea of "feeling happy is good, suffering is bad" and the rest can be built on top of that.