Consider:

Joe, Anne, Greg, and Sue, have $100 between them. Anne has $50, Joe has $25, Greg and Sue have $12.50 each.

Government prints another $100 and distributes it evenly among them. Anne now has $75, Joe has $50, Greg and Sue have $37.50.

But, you say, net real wealth hasn't changed, that $100 wasn't backed by real goods and services. True, very true. So let's renormalize: Anne has $37.50, Joe has $25, Greg and Sue have $18.75. What's the real effect of printing $100 and distributing it evenly? Anne's lost $12.50 of real wealth, and transferred it ($6.25 each) to Greg and Sue. So, one use of inflationary policy is wealth distribution. Of course, you don't have to make things more equitable (the $100 could all have gone to Anne, everyone else would now be half as wealthy as before).

Thing is, that's still a static view. In truth, an economy isn't a balance sheet, it's a transaction ledger, marking activity.

Again, a key problem in an economic recession is a disinclination to invest. This may be reluctance on the part of entrepreneurs, but is more likely a risk aversion on the part of banks. There are two ways around the banking problem: bypass the bankers (direct government subsidy or investment in means of production), or raise the cost of nonparticipation. In inflationary times, money loses value, so the value proposition is to get more of it -- make your money work. Banks have to lend (it's how they make money) or their deposits suffer bitrot sitting in the vaults. As Ben pointed out, if your exchange medium increases in value, it becomes sticky. Remember that money ultimately isn't what you want (wealth is -- but wealth is real things). Unless money becomes a better deal than reality.

No, printing money doesn't "create wealth". It very much can redistribute it, or encourage the creation of real wealth. This is what most people don't get.