I think it depends what field you are in. In printing and publishing, these font differences can create major issues, such as in formatting and readability. You are right, it is not an exact science and can be subjective, but it is important in some instances. Differences in fonts can affect the entire layout of a page. I was watching a video discussing some font and logo design within the Alien franchise, and some of it worked on a level which was very subtle but I believe effective.