Because this is going to lead to less choice of employers for employees, Lower wages for everyone, and less businesses starting up!
Tech jobs are scaling back wages and benefits why should this concern you? because the average google employee only stays for 4 years
 for facebook its 3.7
Where do they normally go? They normally start their own businesses and employ more people! 
Their will be less competition out with less businesses starting up with less wages so any business wont have to pay you as much!
So tech companies taking away employee benefits and reducing pay will lead to less new jobs being out their, less benefits for everyone,
and less pay for everyone due to less employees to choose from capitalism 101!

 Also any environment where some bussinesses

offer less perks is going lead to other businesses needed to offer less perks to keep people
happy up and down the board in differnt fields and pay scales and all in an environment at the moment where everything is going up in price!
Shit runs down hill!
So for those of you Cheering this on and thinking its great DONT! 
We should want the best for human beings and be happy for their success!!!