As a couple of others have said, forum RP is not always necessary if someone does a good job in-game, which is by far the more important factor. That said, forum RP and background stories go a long way to enhancing and fleshing out the character or ship, and I think greatly benefits the community as a whole.
I'm no expert on lolwutters, but isn't it the case that most just get bored and move onto their next abomination pretty quick?
Furthermore, if its takes a couple of weeks to save up for a large cap, (I know it took me longer to save for my juggy + cap7) then that's plenty of time to get something written. Even if it's fairly limited.
Like i said, it's not necessary, but I actually had a lot of fun writing the text and making up the faux photographs and dataslate for my Juggernaught, the ZS-Herculaneum. The same goes for my semi-retired freelancer, Erasmus Fontayne. I don't think it's something which should be looked upon as a chore.