You are correct, some people go only to Disney and some go only to Uni, but many go to both. And they will be compared. They are similar in many ways. Could you imagine Poisedon's Fury if it wasn't in IoA being in 6 Flags? Me either. But I could see it in TDS or DAK or part of a re-imagined Living Seas. Likewise, I could see Uni building Mission Space and on and on. Of course, there are some attractions that will forever be mutually exclusive, Country Bear Jamboree, etc., but the two complexes are similar enough and try to do some of the same things. Or as our beloved @
Goofyernmost so eloquently put it -
As long as this is the case, comparisons will be made.