Greed is too close to ambition. Ambition is a protestant virtue. It is very difficult to separate an ambitious businessman from a greedy one.
No one knows when prices are excessive or when they are merely reflecting supply and demand realities.
No one knows when a salary is fair or obscene (executives, professional sports, celebrities).
No one knows when an interest rate is usuary or a reasonable return on risk.
No one knows when wages paid are fair or modern day slavery.
We can't preach against greed because we don't know what it is!