The idea that double mid doesn't work is a rumor. Double mid can be very effective when your opponents don't know how to deal with it. If you get two mids with enough cc (the one i find that works the best so far is Anivia and Morgana) you can easily dominate mid and get two ap carries fed. The only down side i can see with this strategy is the amount of cs mid gets is dramatically reduced. But if your mids are competent you should be able to secure plenty of kills to make up for it.

there are two reason

1 Normally Mid's have a good escape like kennen rush LB flash or they also have good cc like morgs trap with it being a short lane if you turtle they can;t dive someone with cc being squishy ap so you get farm they get half your farm and not as much levels (the most important thing for mages is their burst take out their levels and you lose a lot of damage.

2 what about bot? you now force you bot 1v2 with a support to stain the ad image trying to play Kog vs taric + vayne...

If you wanted a different mid lane (like, not an AP)
You could try a support and AD on mid.
Top lane at bot (or urgot, GP is good)
Mid lane at top.

;P

So far a mid lane with good cc works the best such as Voli and Anivia (Since the whole point here is to feed a carry and take mid early) And when dealing with bot even if we loose the first bot turret it doesn't matter as long as they don't feed and we take the first mid turret.

It's a suprise tactic, of course it has problems. We know it's not perfect, that's why you wait to use it on someone with poor escapes like Ryse or Karthus, who have scary late games. You shut them down early, and hope you can roll from there.