Why has all the technology today made us more antisocial than the older generations?

As you see in your picture, even in the old day, people are still the same, diving their heads into their own paper but not talking to each other. As for antisocial, society usually only holds one value, especially in the suppressing cultures. In the old days, you don’t get to know that there is other culture or things out there, but now you do. That’s why people get to dislike their culture/society, because they know, some part of their society is wrong, now people can actually “stand their point”. 

This picture is a prose from the book Finding Identity, it talks about it a bit too.

It's like sugar substitute. Social media is easy, convenient, tastes good going down, and removes the sometimes awkward, always penetrating, aspect of in-person socializing.

The socializing of people is roughly the same amount today ... it's taken on new forms as some old forms disappear.

With the knowledge of the world in your pocket, you no longer have to ask people for answers. You can just Google it.

its alot easier to blow someone off