Most are expensive (Wave of Indifference), miss some creatures, (Falter) or work on you too (Bedlam)
On the other side, many green decks are built around Llanowar Elves and Badgermole Cub, using their accelerated mana production to deploy powerful threats ahead of schedule
Kenway bucks the overall trend of the expansion by actually being a very powerful Commander for Vehicle decks and beyond
The administration shifted to Section 122, maintaining the 15% rate
The card selection is bank, but the graveyard filling is awesome, and I take this card every day over the rate of all the Wailing Ghoul variants
So whilst The Ringhart Crest is a card you would never put in your deck on its own, with its restrictions on how you use its mana making it a touch worse than previous variants of this style of card, there is precedent for such a card being worth your time and mana in Standard