AC says: "I can cite the value of the dollar in 1930 to make it look like my profits have grown millions of percentage points, so what?"
AC, you fail to understand even the basics of economics. What do you think "the value of the dollar" is? It's compared to other currencies.
And that's something almost all quoted companies rightfully do.
If you're doing 50% of your business in Europe, and 50% in the US, if you are based in the US and a given quarter, your earnings gros 20% in Europe, and as much in the US, what do you think is the growth of your earnings?
You'd think it would make sense to say that globally, the business has grown 20%.
But no, the official figure is not 20%. It depends on the Euro/Dollar parity. If the Euro is down 50% (or the dollar up 100%, that's the same), then in dollar terms, your european business brings you half as much as it would have done a quarter before (well, actually 60% of what it brought, taking the +20% into account). Does it mean youre european business is less profitable intrinsically? Of course not, it brings 20% more euros than it did.
So it does make sense to give both figures: the earnings in dollars (after all, that's what's really gained in the end), but also the earnings as they would have been if the exchange rates had been constant (because THAT measure is what gives you an idea of whether the business has improved or not).
Of course, one can also just be clueless, and fight to stay so. In that case, it's really a good comment to compare such a usual presentation with using 1930 dollar figures.