It is actually one of the most debated rules in the referee circles.
Why is it there? Because what are the alternatives? What is the difference between a blocked punt and a player trying to catch the punt? What if there was a terrible punt and a player tried to catch a lazy line drive at helmet level 5 yards down field? Block or a catch try if it tips off his fingers?
So that is why the rule works like that. It is just stating that a block is the same thing as a "catch" try. If you touch it, it is a live ball for recovery.
Have I seen this happen? Yes. And I have had to call this in a few high school games on bad kicks. Try explaining this to a crowd of moms and dads... holy cow.
But note that once the kicking team touches it - so if it tips off an offensive lineman's shoulder pads, it is a live ball for the returning team but they can also choose to return the ball to the spot of the first touch - after the play is over. So if a punt tips offensive lineman than return team player picks it up and fumbles after losing 10 yards... they can choose to take the ball at the tipped spot.
So have I seen this happen on purpose? No. The punter has to make a very hard kick, the big offensive line need to duck, the defensive line needs to touch the ball and you have to grab it. Also the ball can't be touched by the defense at or behind the line of scrimmage. So you are telling your o-line to not get hit by ball but also don't let anyone in the backfield...
Could it strategically be used. For sure. Quite possibly if done well enough you have a good 50% chance of gettting the ball back. However in the instances that you would want to use it like a 4th and 27 with 2 minutes left in game... The return team if coached well is in a safe return formation with no returner and no one going after the punter which makes the play pretty unlikely to work. But if you think it will work 10% of the time and your offense would convert less than 10% of its 4th and 27s... than why not?