Most 2h plate users are very easy to fight, and barely ever faint or do anything to make them hard to fight against, plus they are often so slow, a short sword has a decent chance against them just due to it's speed bonus, so a person with alot cheaper gear can easily rip them in to pieces.
And for the thread starter, here's a history lesson for you, the crusaders weren't just knights, play a few rounds in peasant gear as a camp follower or pilgrim and wear whatever gear fits your image of them, and then break out the heavy kit for a few rounds, then back again, also using cheaper gear boosts your speed often times, so you get a semi different play style, just due to the speed boost allowing you to be more mobile, what's wrong with being someone else for a day?
In short, upkeeps fine, without it, every one would be running around with the best gear for their build, and completely rape every RP character and newbie they could find, unless they really sucked...
-Ulrek-