Here it's obvious that tapping a land is irrelevant, because Alice already had infinite mana, and even if she didn't, there's no benefit to having the mana floating instead of stored in an untapped Island
While that deck will certainly have pulled many copies of This Town Ain't Big Enough out of circulation, by itself it isn't the main reason for this spike
The Dirt (The Mana Base) Mono-color decks traditionally have the easiest mana base to build
Once a Modern all-star, Seasoned Pyromancer earned its reputation by squeezing several forms of value into one efficient Creature
Even without adding in any landfall or other mana-based combos, simply playing a fetch land like Evolving Wilds or Terramorphic Expanse will instantly transform Tifa Lockhart into a 4/4 creature with trample
So its tough to trade with, and it puts your opponent in awkward blocking situations