The Static has now become united following the realization that there is another world (yours) that can witness everything they're doing. But during this realization, the Majin Tween realizes her powers as a Staticbender... right as she contemplates suicide, which could cause major catastrophes for the universe she now has the ability to control the mood of since the events of Theater of the Mind.
In addition to this, there is a male viewer out there who is also contemplating suicide, after the darkness of The New Americana influenced him (as all media has the power to do.) The citizens of The Static realize that they have to save both the girl within the Static and the boy outside of it watching on his television.
The selfishness of wanting to end it all could have catastrophic implications for this world, thus this anti-suicide PSA isn't a courtesy... it's a necessity for preserving our universe. For whoever becomes a Staticbender has both universes attaching permanently through their mind.