I mostly look at match results to see how I did relative to shooters I know to gauge how well I did. The class system allows me to do this with shooters I don't know. Does seeing SSP/EX tell me as much about how I should expect to do against someone as seeing Aaron or Jeff N's name on the sheet, no, but it tells me a lot more than just seeing Joe Shooter from out of state.
I think classes are a useful way to track your progress as a shooter, but that's all for me. Does a 1st SSP/MM matter to me in the sense of winning the medal, no. But it does matter in the sense of being a step on the road to being competitive for HOA, absolutely.
The upshot of all that rambling is I think the class system is useful, but I don't care about it that much. A while ago I definitely thought a GM class was needed, but now I don't really care one way or the other.