After a short time, WOTC decided that the cards looked better with a shadow, so they switched over
At worst Gyome always comes with his own meal when he enters the battlefield
Illustrated by Marlene Yui Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp
They also do a good job of minimizing early-game attacks, since opponents are more likely to use their mana on important set-up plays than spending that mana just to attack you
Its most recent jump over the $200 threshold could also have to do with the fact that Pokmon Legends: Z-A and the upcoming set Ascended Heroes have brought Mega Gengar back to the top of fans minds
I have no idea whether or not this will happen in practice, but Glorious End is an interesting effect that didn't exist in Modern before, so it's likely worth considering, at the very least