The question is not about what might have motivated us to take them out, but what our government did to support and/or create them when convenient to do so. (We gave them $43 million last year, and many of their members/agents/soldiers received military training from and/or in the U.S.)
Talk about moral relativism.
I didn't assert that there was any known justification for the American government taking out the Taliban prior to Spetember 11, but our government certainly shouldn't have been subsidizing the Taliban and praising them for being cooperative in the War on Drugs.
Of course, the Bush Administration will argue that they were giving the Afghanistan money to the UN and private relief agencies rather than the Taliban, but without any U.S. monitoring of the distribution of the $45 million, only a fool would assume that the Taliban would not benefit from the U.S. aid. Interestingly, a large portion of our aid was in the form of wheat, which would have the effect of depressing the price of wheat in Afghanistan at a time when America's brilliant social engineers were working with the Taliban to "encourage" opium poppy farmers to switch to (you guessed it) wheat production.