Ah yes but don't confuse wealth creation with greed.
We do need people with the drive to create large companies that in turn produce goods and livelihoods for the vast majority that don't have the vision or the drive and just want a job.
But the wealth created should be distributed more equitably. Yes as the prime mover you should get paid a lot more than the janitor, but at present you have people spending more on a hotel room for the night than others earn in a year. Not that there's anything new in this, it's been the case ever since there was "stuff" to buy.
There are a few that don't follow the greed path, billionaires that still drive their old Chevy and give a large part of their wealth to various causes.
I just watched a documentary on some bloke (I think he is the richest person in China), he still eats with the staff in the lunch room and gives most of his money away.
He has created a huge amount of wealth, given a good livelihood to 1000s of people (presumably or they wouldn't eat with him, either that or they are scared of being fired :)) and not an ounce of greed in sight (as far as one can tell from a documentary anyway).
So I would argue that greed, while as natural to humans as breathing, is wrong and not necessary.
Wanting to better yourself is good, but as I said before once you have more than you need it becomes greed. This is largely semantics though as some people "need" more than others, for example I "need" an Arduino Due while others need health care or a good meal.
Rob