In theory you only buy shares back when you believe that they are worth more than they are trading for. If this is true, it will increase the intrinsic value of the company and should increase its price per share. If it is not true, then management is incapable of evaluating their own business and shareholders should demand that all non-essential capital be returned to shareholders in the form of dividends.
In either case, my point still stands. These things don't matter enough to be bickering about them. From January 2000 to present the Nasdaq is down about 29%, for Microsoft to only be down that amount your adjusted price would need to be about $40. You need to be very generous to say that those dividends we're worth ~$15 and that's just to match the Nasdaq.
If you really want to argue with the data you should be arguing about the start/end dates. Comparing to the Nasdaq eliminates some of the problem as most tech stocks were equally inflated in 2000. I still think you're looking at near parity at best. Microsoft should have been better than average and the data shows that it probably wasn't.