We have talked about that alot over at lpf. It wouldn't take much to add some protection to the glass, but incidents are so isolated, it's not cost effective.
The type of lasers that reaches planes us green because if it's excellent divergence. The thing that really harms you is the 808nm pump diode fir the dpss system. But the thing us 808 alone has horrible divergence. So by the time the dot get up there, most if not all the harmful infrared light has diverged to nothing, and the small amount of green (still dangerous) is what's hiting the pilot. So aside from temporarily flash blinding the pilot, they would not suffer injury. Now of course the claim injury for there own reasons.
So, this even further makes it not worth their time to coat plane windscreens,.