In reply to Offwidth:
The thing to consider is that your 'hand luggage' (aka. climbing gear) weighs significantly more than 5kg. In fact, it probably weighs more than 20kg if you take into account 100m static, a half rope or two, a large Lundy-sized rack, food, water etc... As such, you can see how the amount could rack up if you went via helicopter!
Also, I say 'if', but as suggested within the article I doubt the helicopter ride will account for 1% of climbers visiting the island. From what I gather the 'upgrade' is very infrequently offered in bad weather too, they just encourage you to go a day later or come back a day earlier.