They dont like to see all their favorite cards sent away never to be used, and they find the play patterns of mill decks unfun for their Commander tables
Mulitcolored cards were not included, at Aaron's behest
This is very possible, as a large portion of games in Magic are decided by the cards in your deck rather than simply the cards in your opening hand, but Thoughtseize forces the game to turn into more of a topdeck game
The cards activated ability tells you what criteria to search for
This is brilliant in any tribal brew that includes White, like popular ones like Selesnya Humans around Kyler, Sigardian Emissary to rarer ones like Boros Samurai around Raiyuu, Storm's Edge
While Exeggutor Exs damage is a threat against early-game monsters, if your opponent counters with their own boss monster, it could be an uphill battle for Exeggutor Ex as 40-80 attack is low damage for an Ex