Just because Krypton is far removed from Clark, I don't think it should just die away because he made earth his real home and so on and so on. I do see value in keeping someone's culture alive, even in something as insignificant (to others) as a name. I'm not advocating that they do away with Jonathan Samuel Kent and changing it to whatever's Kryptonain, just give him a name to go with his El roots. There's nothing wrong in honouring both cultures imo. I want him to have that name even if he never gets to use considering how sporadically they use Kal as it is.