Hehe thats really not a neutral view on the subject. The path from bitcoin to real money is short, although you dont know how much money you will get from day to day.
You may argue that selling these machines gives you a more predictable income, but that hardly holds water as the demand surely will follow exchange rate.
The only valid argument left seems to be the timeline of wich the money comes in. If they sell a lot of machines early, they certainly will get the money back slightly faster, so for the buyer, its a highly speculative trade.
The key reason the ASIC miner companies can't keep the machines for them selves is they rely on pre-order capital to manufacture the units, arguably there are "delays" on these units getting to the customer. If you was to have 50 units "testing" for a number of days before shipping you could as a miner merchant make a fair few Bitcoins, note that I say could as this has not been proven and these units do make a big difference to the network once connected especially the 600gh/s units on pre order now.
Sure, you can always use of the shelf microprocessor or even FPGA...but it is much more efficient to use custom made ASIC for this application specifically...I think jury is out...if bitcoin maintains its popularity and appeals to every Joe, and that is a big IF...and if the US goverment doesn't kill all digital currency as they would threaten the US dollar., and that is a small if (they likely try)..then bitcoin CPU actually makes sense, you have to be able to run these encryption operations very quickly if you are paying for coffee or parking with these bitcoins...Kris
It seems that the market appeal of these parallel processors & custom ASICs is similar to the appeal of ever faster network connections to the high frequency traders on Wall Street -- the race to get there microseconds before the other guy. Someone will always come forward with a faster machine, so the "miners" need to make their money quickly, before their hardware becomes obsolete.
But it remains to be seen whether Bitcoin can go mainstream. Meanwhile, it does bear a certain resemblance to a Ponzi scheme.