The reason? They straight up said they have no games to show. Can't get any more clear than that.
Thats actually a lie.
The E3 announcement went like this:
“As the industry evolves, Sony Interactive Entertainment continues to look for inventive opportunities to engage the community,” said Sony in a statement. “PlayStation fans mean the world to us and we always want to innovate, think differently and experiment with new ways to delight gamers. As a result, we have decided not to participate in E3 in 2019. We are exploring new and familiar ways to engage our community in 2019 and can’t wait to share our plans with you.”
The reason they give is because they want to try to put on a differnt show. Thats radically differnt than what they can do at E3.
Necro-bump this 2020: http://gamrconnect.vgchartz.com/thread.php?id=229249
Bumb in 2021: http://gamrconnect.vgchartz.com/post.php?id=9047071