Because you have windshear and you have windshear.
Not every windshear is a microburst, which is what we practise in the simulator.
No microburst in the EK accident.
If I divert every time the wind shifts/varies by 10-15 kts, I would not be doing much else.
And if you, xhamster, had bothered to read this thread before you posted, you would know if WS was reported or not.