It is. And i've never liked it. You cant legislate all risk out of the game
And if that's what you want to do, why bother with a half measure like this? Just say any charge down is illegal. If you attack the ball on a kick its an automatic penalty. You have to be passive in kick defence.
But if you want to allow a charge down, you cant bail out halves for kicking so late throught he line that a defender attacking the ball is at the legs. That's on the kicker and attacking team. You cant get a good clean kick away and the player is onside, that's on YOU. Not the defender.
If you want to say defenders are not allowed to contest kicks, fine. But this half measure is trash imo, and always has been. The rule was put in place as a knee jerk reaction to an extremely dirty play purposely attacking kickers in a way that no one did before and no one has done since.