There are just more creatures that offer value or resilience or indeed produce tokens
Lathril offers multiple routes to victory, combining go-wide with life gain/drain
Mechanics that offer flexibility usually see play somewhere, even if that means you only see these cards in Commander
Some are intended to be played in a unique format or to modify traditional games rules while others were rewards for doing well in tournaments or for participating in events
While Modern and Legacy players are theoretically so invested in the game that they won't quit based on a banning (especially when the banning improves the format), if someone buys their first Standard deck and it's suddenly banned, it's very possible that these players will give up on the game altogether
Once again, we find ourselves facing the effigy of Eldrazi Titans, with a crowd of cultists surrounding them