SkyCycle or 'spent tube cycle' Boris Johnson?

Timeout have told us about cycling underground in reconditioned redundant tube lines with the platforms hosting Boris' bikes.

Although reusing redundant infrastructure is an excellent idea it might be worth asking first why it became redundant.  The old tubes might be connecting places between which few people wished to travel.  Compare that to Foster + Partners SkyCycle which would run above existing railway lines.

SkyCycle complements existing traffic and is in fresh air not a dank underground atmosphere.  It also connects easily to existing cycling infrastructure unlike cycling in spent tubes.  But why not take things a step further?

The bronchs provides the real solution.

Here's to quality cycleways,
Elder Adok