Check your facts: 130,000 points != 130,000 people
130,000 points != 130,000 people At one point during the poll, an unregistered vote counted for 3 points and a registered vote counted for 10 points.
Ubuntu machines have been available from May in USA but only since August in UK/France/Germany. They are still not available in countries where many of the voters live but the poll was global.
Various discounts on their Windows machines were not applied to Ubuntu machines. In some cases this made it cheaper to buy with Windows and install Ubuntu yourself.
Dell seems to have gone out of their way to hide the Ubuntu option on their website.
I am one of the voters and I will buy an Ubuntu laptop from Dell when they decide to make them available in my country.