Hmmm...I have to say, it doesn't bother me.
If someone is Vaping rather than smoking, then I believe (not 100% convinced) this is better for their health than smoking.
If their 'vape' contains nicotine then I would imagine that they remain addicted to nicotine.
If like the fella mentioned, the majority of cigarettes have been replaced by Vape, then I would suspect he is better off health wise, even if only a little. He still has the addiction battle to fight though. (Which he does seem to be in denial of though)
Some people have successfully transited from smoking to Vaping. This has undoubted health benefits. Those whom have rid themselves of nicotine addiction (like us) will undoubtedly say, "great! Now free yourself of the addiction!". I certainly find it dumbfounding if they reply that they are happy to stay Vaping. However, that is their right I guess.
Others do use Vaping as a milestone to being totally free. Not the way I chose, but it's all about the destination, not the journey.
Should Vaping be legal? Well I guess you can't make it illegal while tobacco is still on sale. However, my question to a never smoker who was Vaping would be...
"why?"
"What are the benefits?"
"What would induce you to inhale steam whose only active ingredient is nicotine which only has two useful properties? Those properties being 1. It's very effective at killing weeds. 2. It is incredibly addictive."