I don't want to come across as argumentative because I agree that the way things are, there is so much variability that exists in the SLOEs based on institutions and I agree that these are things that need to be worked on.
That said, the strength of the SLOE comes from the fact that we do not get to pick who writes them. It means that unlike most LORs which get thrown into the trash because they are universally positive (no discriminating features) these actually carry weight.
These letters aren't like the rest of the ERAS application where you can use a computer program to screen - you have to open these letters up and look at them. No way to throw one away because it doesn't have honors without seeing on the same page what percent of people got honors. And so far, despite the fact that my SLOEs do not say honors, every interview I've been in has commented on my "strong" SLOEs. They're strong because they objectively rank me against my peers and that's the part that they pay the most attention to, though you have no reason to believe me if you don't want to.
Yes, a lot of the things that contribute to the SLOEs are subjective, but ultimately their strength is in their ability to objectively compare applicants - and PDs believe that this determines an applicants aptitude as a resident even more strongly than the other objective portions of the application, and probably rightfully so.
The hard part is trying to compare applicants with SLOEs from different institutions. This is why they ask for us to go to multiple places and get multiple letters. If you have lackluster letters from multiple places, it's less likely to be due to the luck of where you rotated and vice versa.
At the end of the day, I think that unless there are vastly more people applying to EM this year, we need to remember that historically there have been enough seats for US MDs (and plenty that DOs get too) and as a result, even a "this student is in the middle third of applicants" isn't a bad grade on the SLOE by any means.