Ah yes, the Cafe, so well known for it's vast knowledge and activity.
Well first basically saying the Cafe isn't knowledgeable or fast enough to your beckon, even with tongue in cheek, doesn't help but anyways...
Saying a player cleared waivers when teams 'could use them' isn't the end of the story. There are many, MANY other factors that go into that conclusion. First being the D-Backs aren't going to just let Johnson or LaRoche just walk away, so when a team puts a claim on him they are going to match whatever it is and then make that claiming squad pay for the player. So whats any difference in just waiting a week to try to make a trade push if you really want that player, and with Johnson the value drops just a bit when the D-Backs know that no one put a claim on him so expectations for what they may get in return drop slightly.
Second, claiming a player through waivers isn't always about improving your team, in fact most of those claims is like playing chess. You put a claim in to block your competitor from getting him. Well the Cards, Reds, Pads and Phils all have good enough options at 2B that they don't really need Johnson. Also while looking at Johnson your looking at just this year, because odds are with a waiver player you're not looking for long term, so going through the whole process to just rent a player just doesn't seem like a logical out when you already have a 2B that gets the job done.
Also the fact that there is still some professionalism in the MLB, basically looking at this situation 'blocking' a player is kind of a douche move (because if a team puts a claim on a player then the team who placed that player on waivers can only try to trade with the claiming team, not allowed to talk with other squads after that point), so basically a team is only going to put a claim in on a player if they think they can get a deal done. The D-Backs have already said they are looking to trade Johnson, so giving him and his contract away would never have happened. Point blank the Cards and Phils wouldn't want to trade youth to get a rented bat, the Braves wouldn't either, the Reds don't need to give away youth because they have Phillips, the Pads knowing that the only other squad then to go after him would be the Rockies who they are ahead of then just let Johnson go. Thus why he cleared waivers, or why I think he did.