Comments like this actually make me angry. It's not constructive and it's factually inaccurate. So lets examine.
"...I think it's a knee jerk over reaction..."
Knee-jerk
adjective
(of a response) automatic and unthinking
Overreaction
noun
a more emotional or forcible response than is justified
Teams and drivers signed a letter the FIA in 2010 to ask for head/cockpit protection - that's 7 years ago. A research program was commenced around that time. A number of cockpit protection solutions were trialled and tested, computationally and by firing a tyre from a number of angles at 225km/hr at instrumented versions, with the halo found to be the best solution. Teams were told halo would be introduced in 2016, teams/drivers/press didn't like it on aesthetic grounds so the introduction was deferred to see if anyone could come up with a nicer looking solution. The Red Bull aero-screen and the shield were both trialled and both had issues which would take time to resolve. So the FIA elected to force through the halo for 2018. I don't see where the knee-jerk overreaction is here, in fact it's the exact opposite of those definitions.
"...that won't help and may hurt"
In an unprecedented move the FIA have actually presented their findings (admittedly it's not a scientific article and few of the actual figures are in the presentation, but let's face it if they did that the press would claim the FIA are trying to hoodwink them with numbers and scientific jargon), but we know it will definitely help in most situations, both object-to-car and car-to-car. The only weakness, to which they admit, is in small object-to-car. Which a) it is not designed for and b) helmet rules have been designed to further protect the drivers from small objects.
The only emotional and unthinking response is yours, and I see your comment as, "I don't like how it looks so I will try to pick holes and make unsubstantiated claims that it's actually dangerous".