Meh, I would love to have someone better at the #1 CB position. Younger would just happen naturally. Kevin Johnson is younger. I don't want him. JJo is rated as the 12th best CB in the league by PFF. OK, you can quibble with that ranking, but honestly, not by a lot. Who do you want better that the team can get? The only path to upgrade is through the draft (remember Kevin Johnson, 1st rounder?) or by free agency/trade (remember Colvin, who was inactive for the playoffs?). It's easy to say you want an upgrade, but not easy to get one. And having the 12th best CB in your #1 spot is not the worst talent deficiency on this team by a long shot. So if you're going to spent capital on upgrading, don't you think it should upgrade the spots where the team has the bazillionth best player (looking at the OL)?
Not saying you shouldn't upgrade, and I said upthread I think one of the first two picks should be spent on CB, but there's no guarantee that draft pick turns into the next Jonathan Joseph, much less Ramsey or similar. Good chance it turns into the next Kevin Johnson.