Scottish Premier League clubs voted on proposals to introduce a new 12-12-18 league structure this afternoon, with the system designed to bring added revenue to football in the country.
However, Ross County and St Mirren voted against the changes and, with an 11-1 majority required to pass it on to the SFL, Thompson believes that they may have missed their best chance to change Scottish football for the better.
"The proposals would have attracted new sponsors and advertisers and, more importantly, encouraged more fans to attend the exciting and vibrant spectacle we are producing on the park, as was witnessed in the two William Hill Scottish Cup semi finals at the weekend," said Thompson in a statement.
"At Dundee United we were not happy with a number of issues in the proposals, but we preferred instead to look at the undoubted benefits of the overall package for the game as a whole. All SPL clubs were given ample opportunity to express any concerns during the many months of consultation.
"In an attempt to overcome some late concerns, concessions were made on the day with regard to voting of 11-1, but these were not even allowed to be amended; never mind voted on!? Despite all of this, two clubs today decided to vote in a certain way and my belief now is that it will be many years before other proposals backed by so many will reach the table again."