It is more along the lines of whether or not Utah actually adds financially to the conference. Meaning how many viewers do they actually bring, how much prestige do they add, how many of their fans buy tickets at the other schools venues, do they actually add in negotiations for tv contracts (think of how they have been unable to get on Direct TV), and other factors like that.
Utah could win every game in every sport and if they didn't actually add value for all of the other things they'd be a negative addition.
My guess is they add very little value in those things, small fanbase that doesn't travel, second place in viewers and fans even in their own market, direct tv couldn't care less about them, they just don't move things along, they're just kind of there. I doubt they are dilutive but they probably aren't additive either, they are just there.