It might not make sense for you but look at this, Rollbit is trying to encourage potential customers to deposit NFT onto their platform with a small benefit of getting loan with the NFT as collateral. Obviously Rollbit is a gambling business not a money lending business so it just doesnt make sense for them to offer you longer period of loan
This is the real point don't be fooled the main focus of rollbit remains on the gambling market they won't write ''borrowers have to gamble here'' It will not happen
But that's the real goal introduce rollbit to NFT users then attract their attention to gamble really a smooth marketing strategy if this program is not profitable Rollbit will definitely close it in the future that's how business goes.
That's what makes them cool since they always do proper things just to gain success and actually by joining the NFT scene make them smart knowing how big the market of this industry and they can accumulate bigger audience for their participation on that scene and not surprising to see how successful they are right now knowing that they have great marketing stuffs made.