The wash sale rule seems to have been created without much consideration of the retail day trader who might want to buy and sell the same stock multiple times in a day and for extended periods of time. If you do the accounting the way the IRS would like you to do it, you can have somewhat of an accounting nightmare on your hands, especially if you have thousands of wash sales to account for. The IRS does permit you to adjust your basis on the repurchase by the amount of a loss, but it can quickly become an accounting headache unless your accounting is quite automated.
One way around the rule for a day trader is to qualify as a full-time, professional trader and elect mark to market accounting. It seems that is a topic that's been discussed many times here on ET.
I wasn't really thinking of day traders, I should have been though, when I said the wash rule keeps us from selling to create a tax loss in a particular year, and then immediately reacquiring the same stock. For day traders who can't use M2M accounting it adds complexity to their accounting, if they are going to do it the way the IRS wants them to...