I find those statistics to be staggering. Less than 10% of people bother submitting their games? Why bother downloading then?
Let me think here, when first joining a GOTM. I've played with 3 now but not submitted...mind you one i could have submitted and didnt, and one i left unfinished, because i didnt understand the exact meaning of a "reload".
However, the third one i tried, was not with a plan to submit, but more to see how well i coped with the settings and a change of strategy, and if i wanted to (though i didnt need to) i could reload the game over and over and over and compare what score i got with those who submitted. I think there is an underestimate of the download and play ratio compared to download and submit.
There are many reasons someone wouldnt submit:
1) They die.
2) They want to practise and reload and compare scores.
3) They are bored and just want to try a new tactic on a map with a decent capital.
4) They score too low and don't want to look bad.
5) They score too high (but not high enough to be happy) and would lose their adventure class access (because they think only way they could get an award is with this option).
I expect they are the main reasons? Most newbies would struggle to get a decent score on anything above noble, I play monarch typically but i've been playing civ since the original? I watch newbies play and struggle on noble and could see why the just wanna play the game but not submit because they simply can't compete.