Pop reports are more popularity reports than accurate measurements of grading difficulty, but just look at the numbers of PSA 10 EX full arts during that period compared to later XY, SM, even older eras like EX
This could be a big play to keep any fully evolved cards off the Bench and allow you to prevent a retreat into something much stronger
One of the keys to winning a Pokmon Pocket battle is for players to get as many cards into their hands as possible as quickly as possible
Similar to Greninja, it is also done in a more traditional art style
That said, I still feel Curse of Vitality is overall a weak card that won't see much play, but it still is a decent inclusion in Lifegain decks that can take advantage of the trigger, such as Oloro, Ageless Ascetic, Karlov of the Ghost Council, and many more
Maybe you are playing a deeper game and plan to win with decking or some other exotic method