Windshear is primarily a large aeroplane problem, it's not generally significant in anything this light.
So given the same amount of windshear off the end of a runway a light aircraft could land in safety but a large airliner would have problems-sorry that sounds ridiculous to me!
Which is a shame, because I'm sure that if there were enough known, there would be lessons from this accident that could aid all of us. We may be able to draw some useful conjectures once we do have AAIB's reports - but only "may" in my opinion.
Apart from the stupidity of the conjecture about a sucessful businessman taking risks, useful conjecture, even at this stage maybe- Dont fly in weather thats outside your experience or outside the privelleges of your licence or rating. Dont put yourself(and your passengers) in a situation where you feel you have to get in. A diversion may cause inconvenience but its always better to be inconvenienced and alive than otherwise