I am working with a Bitcoin mining company. We have our own datacenter using hydro power. I would agree that individual consumers buying hardware and running it themselves is not economically viable. I would also agree that there is a lot of background noise and outright scammers.
The value we see is that BTC has the potential to disrupt banking including payment processing, money transfer and ecommerce. Large companies are now accepting it as a means of payment. Expedia and Dell are two examples
It is also a protocol that goes beyond banking - the underlying technology could be used for many things where validating identity without a 3rd party middleman would be useful. Examples include the exchange of contracts and voting systems.
We see Bitcoin disrupting many industries in the same way and at the same scale as the Internet has already reconfigured media and communications.
Whether it will succeed and how it will do so is highly speculative - its difficult to imagine that the concept of digital currency is not going to play out to the benefit of the consumer, maybe starting at scale with the 3 billion new folks that will have mobile internet access but no bank account within the next decade.
Just my 0.02BTC :-)