No one is arguing that FT doesn't have more/better access to Chant than TES does, adding 4 top deck tutors and 4 Sensei's Diving Tops with shuffling effects is going to have that result. The problem with the FT vs TES disruption argument is that FT MUST have more/better access to Chant, because it's slower and it gives the opponent more time to assemble his counter walls and lay his permanent road blocks

On the other side of the FT vs TES disruption argument, FT's Fetchland manabase and acceleration can't support Vexing Shusher as well as TES's 5c manabase and acceleration can. In FT, there's a push/pull effect on its SBing from either bringing in anti-counters and/or anti-permanents, where TES can bring in a single, uncounterable card that deals with both counters and permanents at the same time. TES also gets to bait counter unto acceleration or Burning Wish because of the threat of Empty the Warrens, or it can just Burning Wish for Thoughtseize/Cabal Therapy.

As far as Vexing Shusher and Empty the Warrens being prone to removal is concerned, it's advantageous to TES, because it makes SBing more difficult for the opponent. He has to choose between keeping in 4 to 12 dead cards at all times, where for FT the SBing is much easier sans Tomb of Urami or Dark Confidant etc.

I'm not convinced Extirpate is worth it, most of the times I've drawn Extirpate I didn't have Orim's Chant, which leads me to believe I'd rather have drawn Abeyance and either be able to go off from there or double chant.

The speed argument is relevant, we aren't mispiloting the deck, FT is just one to two turns slower than other storm combo decks on average. You pay a price for your card selection, and you pay it in speed; it's the defining attribute of FT, and you can't simply dismiss it.