If its not done right you haven't redirected the lightning.Actually redirecting it doesn't make it any less dangerous. You could die easily if not done right.
To be honest, I'm surprised Mako can generate lightning AND redirect it. Being the second bender capable of doing both. (The first being Iroh.)
Some of the high-end bending techniques seem to be becoming commonplace. Generating lightning took serious skill in the first Avatar series yet in LoK there's entire powerplants filled with people doing it. I've already mentioned my issue with the metalbenders (I really don't think there should be enough to make an entire policeforce of them). Its just the march of progress. Things are moving on and as more people learn the techniques they imrpove on them slightly making it easier for the next generation.