Colorado wasn't CHANGING eligibillity or disqualification rules for office, they were trying to ensure votes of their state were not wasted on a candidate who was ineligible for office and would be / should be blocked from TAKING office.

Colorado was arguing that its state courts had the right to determine whether a candidate met the eligibility requirements set out in the Fourteenth Amendment. SCOTUS looks poised to rule that states don't have the power to make that call. If states can make that call, then different states can (and certainly will) adopt different interpretations of what constitutes an "insurrection" or "aid or comfort to the enemies" of the U.S. They can assemble different evidentiary records for making those determinations. And thus, states would be granted enormous amounts of discretion to fashion those outcomes in different ways, depending on the political predilections of the States.

In short, the USSC views the rights of an individual CANDIDATE to have every possible chance of attaining office to be more important than the rights of millions of voters to clearly understand who is likely to take office based on their vote.

They haven't issued a decision yet, but I imagine it will not be based on the rights of any individual candidate. Rather, it will be based on the limits of state power. Specifically, that States aren't given the power to interpret the Constitutional eligibility requirements for themselves - regardless of whether their putative interest is to "clearly understand who is likely to take office" or any other goal. That's why Roberts' observation was so potent. The entire thrust of the Fourteenth Amendment was to restrict States and give power to Congress to make them behave. The idea that this created a backdoor mechanism where States could decide for themselves who's giving aid or comfort to the enemies of the U.S., and block candidates based on it, is inconsistent with that general purpose.