One of my favorite recurring bits from investor Peter Lynch's writing is his annual lament that, to paraphrase, goes something like, "Why in the H-E-double-toothpicks do I still own IBM (NYSE:IBM)?"

That heretical query was the first thing that came to mind when the market started to cheer this morning's major rumor-cum-news that IBM was planning to sell its personal computer business to a Chinese firm for around $2 billion. My response was, "Are they nuts?"

After all, most of us got our introduction to IBM and desktop computing through the PC, not the over-amped, backroom brainiacs that created the firm's first fortune. This is akin to Microsoft (NASDAQ:MSFT) giving up on Windows to concentrate on some kind of command-prompt nightmare.

How could IBM give up the PC? It's not like the products aren't popular. They sell to the tune of 10 billion bucks. And a cursory check of the most recent 10Q shows that the PC biz has been the strongest revenue grower for the company so far this year. It's been growing at a 17% clip, nearly four points better than hardware as a whole and double the pace of the biggest revenue generator, global services. That puts PC sales at 13% of total revenues this year.

Word on the street is that the PC unit is a perennial money loser, and if you dig deep enough into the 10K, you'll find the evidence -- though you might go blind before you realize that the red ink isn't so deep.

But here's the real question: How in the heck can one of the world's biggest names in technology fail to make a profit on such a big business?

Don't tell me it's just commodization and competition from Dell (NASDAQ:DELL), Hewlett-Packard (NYSE:HPQ), or dozens of smaller firms. At any time during the PC revolution -- even now, some might argue -- IBM should have been able to use its buying power, reputation, and technological expertise to outrun the competition or squash it. IBM couldn't, because it's impossible for a 100-ton dinosaur to run a 4.3-second 40-yard dash or aim a size-500 foot at an insect.

So while everyone else is celebrating the day that IBM shed its PC anchor to compete more directly with Sun Microsystems (NASDAQ:SUNW), HP, Red Hat (NASDAQ:RHAT), or whomever, I'll be wondering this: Why would anyone think that Big Blue will fare any better in the upcoming race against smaller, faster opponents?

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Seth Jayson will almost always bet on the quick mammal, not the dinosaur. At the time of publication, he had positions in no firm mentioned. View his stock holdings and Fool profile here. Fool rules are here.