Barring a few babies and children and whelps, they fly, they are big, they have a higher price tag, and they win you a ton of games
With Morph, you dont have to wait and hope you pull another copy of the card you discarded, because you can just play a different Shift character instead
It seems wizards is more focused on incorporating life gain into other cards with static abilities such as lifelink on creatures, or as an afterthought of a "choose two" card
You can also do this combo even better with any sac outlet (Ashnod's Altar) + Renata, Called to the Hunt or Master Biomancer + any persist creature (Woodfall Primus)
If you were going to run Extinguish All Hope, you may as well run this instead
Drop this on something like a Mayhem Devil and you have a very dangerous situation, and it's a cantrip, and you can cantrip it onto an equipment so your opponent's can't so easily 2:1, however that's a lot of moving pieces for a pinger with deathtouch