If it can't be used as a currency, and it doesn't make a profit, then why should you buy it? If you figure that out, please let investors know because most can't come up with a good reason (beyond selling to a "greater fool").
Exactly! That is the sentiment of most potential investors right now.
I do feel that there is legitimate potential for speculative investors to make money by investing in Steem/SP. Most likely (in my non-professional opinion), the price of Steem will go up if/when the site moves out of beta and (hopefully) becomes more mainstream.
At some point though it will reach a point where there are no more speculative buyers left to push the price higher. Ideally it could reach an equilibrium where the price remains stable enough for the SP holders to beat out the inflation with the SP interest. This I think is the best argument in favor of "speculative" buying.
There are two potential game changers that Steem/it could implement - which would add significant value to the investment. One would be to tap into the "game" portion of the site, and hopefully get millions of people to power up (mostly in small amounts). The other way would be to find some way to commercialize on Steem/it in some way, such that the holders of SP would have the potential to be making some type of profit.