re: Why do WRs get injured just landing now?

Guys are too big, too fast, too explosive and playing in way too much space where the above attributes are being used more frequently. It results in more violent movement that connective tissue cannot keep up with.

Do the cleats hold to the grass too long?

Hasn't tackling changed? I sort of remember simple one on one tackles. Now the defense grabs and swings the offense around and two more join him to down the runner / receiver., That offensive player may be disoriented and less prepared to land safely. Inner ears don't adjust ot disoriented training.