Because it’s feedback on how effective their targeting has been when confronted with whatever electronic warfare and misdirection Israel was using to defend themselves.

That sort of information might let the attacker make adjustments to be more accurate next time

ever play battleship, the board game? it’s like that. it would be much harder to play the game if you didn’t know whether you hit or missed a target.

If you know you hit a parking lot 500m east of your target you aren’t going to miss the next shot.