I vape, but I wouldn't do it in the stands, basically as it's banned and inconsiderate. If I didn't vape, I think I would much prefer that over someone dropping ass biscuits next to me all game mind, or some ****-head talking crap.
I can semi-understand why they do it, as vaping you need to keep constantly topped up with nicotine, it's not like a cigarette where you get an instantaneous hit, and it can last 45 minutes or whatever. It's not an excuse though, either accept the rules or don't go.
The thing is, when vaping, you can take it back and not even breathe out any vape, so I'm not even sure why people would create clouds of vape, other than the amateurs. The amateurs (those passing them around) are likely only doing it as they're drinking, as booze massively increases the urge for nicotine if you're a casual smoker.
The yobbish behaviour on booze is probably worse mind, and overall more damaging to others, as (from studies) inhaling vape seems about as dangerous as drinking coffee or having a microwave meal, and breathing it out is probably far less than this.
The club should allow vaping in small areas of the concourse though (smoking still outside), most people vaping are doing that to try and get away from actual smoking, and they need all the help they can get (especially when drinking).