I think that is an assumption and simplification. Greed is different than love of money or lack of it. So I would suggest that greed can be a cause of evil but not the only cause. Love of money can be quite healthy. Lack of money is not directly linked to evil at all for most. It may lead to a less fulfilling life but many lead evil free lives while living in poverty.
Jealousy is a terrible thing and leads to much evil and has nothing at all to do directly with money.
Vanity is another source of evil.
Insanity is another source of evil.
Ignorance is another source of evil.
Religious beliefs are a huge source of evil.