This is so new though. The first ecig came out in China in 2004 and it took a few years for them to gain any sort of popularity. They were all very low wattage devices until just recently. We really don't know what the long term effects of these things will be, and it may very well be that super high wattage setups are much worse for people heating these juices up more with all the various chemicals in them that may be perfectly safe as food additives but not necessarily when heated to the point of vaporization and inhaled in large quantities.
For me, these are nicotine delivery devices. I've done the super low wattage devices with juice at 36 and 24 mg/ml nicotine and did not like that. You get barely any vapor and the nicotine flavor is overpowering and when you get juice that strong in your mouth it hurts and leaves a horrible taste for a long time. Those old ego batteries and high ohm tanks were only using something like 5.5 watts though and the more you increase your watts the lower the percentage of nicotine you need in your juice to take in the dose that it going to satisfy your cravings. Good flavor and a satisfying amount of vapor can be had at much lower than 60, 80 or more watts, but different tanks with different atomizer heads do all have their sweet spots and the higher the watts a particular setup can take, the more watts you need to push through it to get to that sweet spot. I've noticed that even with the newer Kangor Subtank vertical OCC heads compared to the horizontal coils in the older ones. I have both. You can push more watts through the vertical coils without getting burnt hits, but you need to push more watts through them to get the flavor you got from less watts using the older coils. The industry push is for higher and higher wattage mods along with atomizers that can take higher watts, which just means people will be consuming more and more juice, which is probably only a good thing for those selling the juice (and batteries and battery chargers). It's probably not healthy for those consuming it. It makes vaping a much more expensive habit, buying all that extra juice you will go through pushing extreme watts and the gear you need to do that. It makes vaping more annoying for those who don't vape, which is only going to help get anti-vaping legislation passed. I wouldn't be so sure that inhaling massive quantities of vaporized e-juice is so harmless, and I just can't see how this trend of increasing wattage is good for anyone except those selling juice.