He mentions politicians every time the chorus comes around. That is what “rich men north of Richmond” means. That’s why he isn’t calling out wealthy people south of Richmond. DC is north of Richmond.
I can’t tell you why the song is popular, but I can definitely parse the meaning of the lyrics, which you seem to be struggling with.
These rich men north of Richmond
Lord knows they all just wanna have total control
Wanna know what you think, wanna know what you do
And they don’t think you know, but I know that you do
'Cause your dollar ain’t shit and it’s taxed to no end
Cause of rich men north of Richmond
This is explicitly about politicians. The entire song is.
The only other lyrics with any content are
Well, God, if you’re 5-foot-3 and you’re 300 pounds Taxes ought not to pay for your bags of fudge rounds Young men are puttin’ themselves six feet in the ground ‘Cause all this damn country does is keep on kickin’ them down
Lambasting “welfare queens” and taxes.
Needless to say, this song isn’t popular with me, because I am capable of understanding both the lyrics and how taxes and welfare work within the context of the economy.
At no point does he decry wealthy business owners or anything of the sort, which sort of takes away from your “any political leanings” argument. This is very explicitly one political leaning, and from a person who isn’t very knowledgeable.