I'm asking this out of curiosity, not attacking you, since you said yourself you're not creative and rely on these people for their creative talents.
For instance, I can't cook much more than eggs and bacon, but I can sure tell whether a dish at a restaurant is any good. And I can even narrow down a dish's quality into various broad classes: disgusting, bland, okay, good, really good, and great. Most other aesthetic creations are similar.
You can no whether or not they work for you without knowing why. But the nature of subjectivity is you can't know whether they work in a more general sense without analyzing the elements of the thing in question against an accurate-enough picture of the distribution of tastes in the population.
Just because you like or dislike a particular creative piece doesn't mean that you have what it takes to dictate a piece of creative work that will be exposed to millions of people.
Is the image very busy? I may know that I'm going to want to use it along with other assets or in presentations - how is it going to affect that? How do the colors and shapes used compare to other assets it will be used beside, how will it work in different mediums? Bright yellow isn't great for projectors or for legibility.
One example - a global accounting firm introduced a new framework. They had a diagram that had core elements, supporting concepts, and overarching concerns. It would work fine at full size on a laptop but was very poor for display on a low res projector to an audience of 100. This design was core to the effort and would be used in very many situations with projectors to large audiences.
I may say that I want to look like James Bond skiing - you design me a yellow ski suit very similar to the intro of The Spy Who Loved Me. I'm horrified because I want a look similar to the all black look of Daniel Craig in Spectre. My inability to communicate about design created a problem but I can judge on whether or not you've achieved my goal.
Translation across domains is VERY HARD.