They are much better than anyone you idolize and look up to.

Excalibur is the legendary sword of King Arthur.
Skits wields the best weapon, a symbol for lyricism, skills etc.

Gingivitis is inflammation of the gums (gingivae)
The people who copy him(biters) are sick with gingivitis because of biting(copying) his raps.

Their lyrical skills are so good it only takes them about a minute each to pulverize phony mcs.

They are destroying everyone who has no real skills.

The theme question of the song, followed by the answer. Dope D.O.D is now the best.

A question we all ask ourselves.

Jay is saying he is much better than these guys.

He is the best but he doesn’t work hard. He doesn’t copy others or even learn from them so Jay-Z doesn’t really ring a bell.

Or he doesn’t own a TV, either one.

You don’t want to be run over by these guys.

When he sees haters and people who don’t give him credit for his work he just blacks out and destroys them.