Let's say you were forced to invest all your savings in either a PoW or a PoS currency; no other investments are possible. Say they both have the same block reward, which is essentially inflation tax.
Since you'll have to pay inflation tax either way, wouldn't you rather invest in the PoS currency, where the tax is redistributed to stakeholders including yourself? Rather than the PoW currency where the tax goes toward hardware and electricity bills.
That's simply not true. You could potentially loan out your Bitcoin to a company which would play to use that money to create a profitable business. (Of course, it's a bit trickier to do that with Bitcoin due to the deflationary nature, but that's another story.)
When you stake your coins, that's not quite possible.
We can tweak the scenario to say that you're forced to buy and simply hold one of the currencies, without loaning them out or otherwise touching them for 5 years. Then clearly PoS has the advantage.