Psprocket, hate to say this but you are mistaken and Seerah is correct in this, I logged in to my character and disabled all my addons EXCEPT EquipCompare and it does not compare stats as you are describing. And in fact to make sure there wasn't a setting for it in equip compare I checked the options and I believe the only options EquipCompare has is to show on certain modifiers instead of all the time, to disable it and actually I think those are all the options. So I would recommend checking your addon screen for each addon you might have that affects tooltips as you might find what you are looking for. Below I have posted what equip compare does with a link I clicked on from the chat window and I assure you it looks the same even if I had moused over the actual item.
This is all EquipCompare does. So unless you have some weird funky version of equipcompare which I doubt its most likely ratingbuster or another addon like it as previously stated by Seerah.