"Holding" on Blocked Punt

[Hampton Roads 6]

I saw a play Saturday that I have never seen before.

Team A is punting. Team B 'brings the house" and blocks the punt and recovers inside 5 yard line. Flag on play, Team B is called for "holding" before the kick. Why would team B have anything to gain by holding if in fact they did ?

 

[White hat]

When the defense holds it's often grabbing a blocker and pullling him out of the way of one or two rushers. Faily common but missed a lot.