The problem with the L&K was that it was way to easy to obtain, for how good it was. By sealing it, you could make up for that mistake in a 'fair' way.
Everyone can decide for himself if he thinks he needs the L&K that badly to go through the trouble of unsealing it.
Or since we are working on the prestige system, why not making people that have prestiged x amount of time able to use the combo unlocked version? Just suggestions.