There's nothing wrong with trading Bitcoins, just like there's nothing wrong with exchanging USD to EUR to buy a glass of wine.
Yes, but if you are spending a lot of time or effort trying to make money on an essentially unproductive activity then I think you should ask yourself if there's something else you could be doing that would be more effective at making the world a better place.
I think a lot of buy-low-sell-high, there-is-always-a-bigger-fool, or high-frequency trading fits into the "isn't making the world a better place" category. If you're competing for a bigger slice of a fixed-sized pie, I think you should think hard about what you could do instead to make the pie bigger for everybody.
Mmmm.... pie......
Maybe I spend to much time on the speculation board, but it seems to me that a healthy portion of us don't give two shits about making the world a better place, and those who do tend not to agree on what that means. And all this matters relatively little since an even smaller number of us have the native ability to contribute anything of substance anyway.
In the mean time, I see all the trading and scheming as quite useful as a means of stress-testing the system and exploring facets of it which might not be thought of by the more capable developer class. I think that it is a huge net positive for the network as a whole at this time particularly as the economy is much smaller than I would have imagined given it's (what I consider to be) quite revolutionary nature.
In order to explain the lack of interest and 'success', I have settled on the philosophy that the current state sanctioned currency systems are working fine and actually work much better than Bitcoin ever could
(for now.) Whether my explaination is correct or not, it is hard to deny that if the world population cannot absorb the current rate of inflation with more ease than seems to be the case, there seem to be issues. Again, I see it as a big net positive that there is fair amount of trading interest and activity and that at least one example of the system making people $$$RICH$$$ at one time as psychological tool, at least, and one which is likely to pay off going forward if the system hold together. And speculative interest can be thanked for that I think.