Wealth is often defined as the ability to give. Bill Gates certainly understand this with his Foundation.
Wealth is ok as long as what is given is not taken from someone in need or from someone in the future.
It seems to me that today's wealth is partly borrowed from future generations.

Going back to the "hoarding" topic imho hoarding cannot be lethal for the BTC economy because bitcoins can be used as a meta-currency.
The value of bitcoins in this use case stems from the merits of the bitcoin network as a transaction processing network.
Goods can be sold in state currency with bitcoins being used just as a transaction vehicle (converted in real time at each end of the transaction).
Transaction fees over the bitcoin network can be competitive compared to card schemes.