So which party is being dishonest. The colleges that have an all scores rule assert, as others do, that they use the highest scores to determine admission and do not hold lower scores against you. The all scores rules started in early 2009 quickly after College Board announced it was adopting score choice. The first to chime in with an all scores rule was Yale, which screamed the loudest about College Board doing something it had recommended against. Carnegie Mellon and Georgetown were also among the earliest. By March 2009, there was a long list of all scores colleges which joined the fray mainly because others had done it.
Until that time, no college had ever had an all scores rule, including for the ACT which always had a form of score choice because it only sends one test per order. A minority of the colleges that adopted an all scores rule for the SAT in 2009 also adopted an all scores rule for the ACT despite allowing score choice on the ACT for over 50 years, i.e., they did not consider any need to do what is suggested by socaldad2002 above in comparing test scores for over 50 years with the ACT. They adopted an all scores rule for the ACT in 2009 simply beause they adopted one for the SAT.
Despite adopting an all scores rule, the colleges continued to claim that they used the highest scores to determine admisison and did not hold the lower scores against you. For almost two years after adopting the all scores rules, no college stated any logical excuse for having it except for being pissed at CB and asserting they needed all scores. About two years after the all scores rules started, some colleges came up with the excuse that socaldad2002 mentions above, in that they needed all scores rules so they can see the the test history of the candidates and and consider how many test were taken to get the best scores. Once that excuse appeared for a few colleges, it became the one for almost all colleges that adopted an all scores rule.
There is one major problem with that excuse. It is just a clever way of saying they will actually use lower scores against you without specifically saying it. In other words, i.e., if they decide a candidate with a 1500 SAT score after taking one test is is somewhat better than a candidate that has a 1500 only via a superscore, then that necessarily means they have used lower scores against you. Thus, the clever excuse colleges created is the oppposite of their claim that they use the highest scores to determine admission. So if anyone is dishonest, it is the colleges that have an all scores rule.
It is now more than 9 years since the all scores rules were first adopted. Since then, every college that had the rule has ended it except for six: Yale, Georgetown, and Carnegie Mellon (three of the earliest to adopt such a rule, although Yale and Carnegie Mellon have ceased applying it to subject tests), Barnard and Cornell (which strangely now accepts score choice for the SATs but still requires all ACTs), and potentially the UCs for the SAT (oral communications by many with the UCs have indicated they really don’t care if you do not submit all scores).
In other words, every college in the nation except the six have concluded getting all scores is not necessary. The alleged unfairness above, that not getting all scores would be unfair to those who take the test only once and score high, is something obviously that every college in the nation, except the six, has either decided is not a problem or possibly decided that doing such a comparison would be dishonest because it violates their claim that they only use the highest scores to determine admission.