romp
There's only one romp with an excellent rating. Do people rate dmods based on their length, or are romps generally worse than quests or epics?
Actually I found 3 Excellent romps... but yeah, I think the length contributes to the review score of the game. Imagine a kick ass FPS game with only 2 levels/maps or a kick ass racegame with only one track. But still, you can make a very short romp of 1447 quality but I don't think it'll score as high as an average sized romp of the same quality (or even quest/epic length).
Romps are generally worse. Newbies nearly always first release romps. Of course some start making quests and epics (start by opening all the map squares, for example) the first time they make a mod, but they end up either not releasing anything or releasing a short, buggy romp with a large map.
I would say both. Most romps have a lot of bugs and even if it is bug-less its hard to give a high score for a DMOD that only last for a few minutes.