Only a guess as I do not have the facts, if the weather is too bad to fly at Lands End would it not also be likely it is too bad in the Isles of Scilly?
I do think Skybus could have a bigger role in a future of Newquay but as I have said before they have a lovely little niche operation with little risk and zero competition so why go into something else that would endanger that position?
Problem is of course all this is rearranging the deck chairs on the Titanic, a handful of flights to London or not isn't going to change the airports economics dramatically or go anywhere near covering the current massive losses.