Ah, yes. Not surprising that the non-engineers jump on the number of screws. Tell me, oh clever one, how much worse is it with 2 screws than 4? That's right, you don't know. You only assume that 2 is worse. Could it be that the remaining screws were larger, or worked in a different way? Your steering wheel in your car is held on by one nut. Would two be safer?
And as the visor coming loose didn't make any difference in this accident (other than, perhaps, absorbing a small amount of energy from the damage from Felipe's face) why get in such a hissy fit about it?
What if the threads of the screws had been the cause of the damage to Massa's skull? Would you then be saying they should have gone to two screws (imagine, if you will, that they had kept 4 screws for this example)? What if the remaining two screws had moved and pierced his skull? Would you then like no screws?
I love it when ignorant people make stuff up. And in F1 threads there are few more clueless than Mustafur.