Its fun, it causes interesting interactions, and some effects even play well with the increased use of negative counters like finality and stun counters
You can play Hoopa-EX down on your field and with it you can get Shaymin-EX, Rayquaza-EX and M Rayquaza-EX, and then you can play the Rayquaza-EX and the Shamen-EX and draw a card, and you can draw into your Rayquaza Spirit Link (XY 87/108) and attack the Spirit Link to your Rayquaza-EX and Mega-evolve immediately
The set offers an exciting opening experience while maintaining strong collector appeal
Phelia, Exuberant Shepherd and Ephemerate are the gold standard for blink cards currently, and Airbender Ascension is slower than both
This kind of product should have been priced like the Battle Academies, which are literally the same thing minus the nostalgia and some of the cards from that being tournament legal (even if they're not competitively viable)
The staff-only iteration then took it a step further by the word STAFF in all-caps on the cards left side