See
here.
I'm all for this rule change. The catcher has an unfair advantage: shin guards and other protection. No other fielder attempts to block a base due to the fact that taking a hard SPIKED slide can cause serious injury. But catchers use their shin guards (and chest protector and even mask/helmet) to block the plate -- something they would not attempt without all that gear.
And when the catchers block the plate, the runners realize that sliding will be a near certain out since they can't even reach the plate. So the runners collide and it looks cool -- except when injuries occur.
Enough already. Many other baseball leagues have outlawed these collisions long ago. Make the catcher field tag plays the way tag plays are made at the bases: catch the ball and tag the runner.
BTW, consider a runner attempting to steal second base who decided to plow through the shortstop rather than sliding. That would be considered a very dirty play. But when a runner plows through a catcher, it's considered a "clean play."