Four mana for exile reads expensive next to Stomped by the Foot and Bot Bashing Time, which both clear threats for two or three. The tap clause is the reason: this is not removal you cast to answer a problem, it is a tax on creatures that have already committed. It cannot touch Shredder, Unrelenting the turn it lands, only the attacker that swung last turn or the body an opponent tapped to push a Sneak trigger.
That punish axis is more relevant in TMT than it would be almost anywhere else. Sneak shows up on 59 cards, so opponents are constantly tapping creatures to push damage or fire abilities, and Henchbots converts those lines into a clean tempo swing. The 2/3 body holds up too: it trades evenly with the format's 3/2s and blocks the 2/2s without dying, so a dead exile clause does not leave you with an embarrassing card.
The seats that want it are the colorless-leaning builds short on white or black removal. UR Sneak shells need a catch-up answer to a threat that has stuck, and any deck splashing through a TCRI Building or Foot Headquarters wants a colorless insurance card that does not strain the mana. P1P7 to P1P9 in those seats, later in colors already holding Stomped by the Foot at common.
Maindeck one, sideboard the second. The failure mode is drawing it into a board of untapped blockers with no combat coming, where it does nothing but sit as a 2/3. In a slower deck without removal density, that risk is acceptable; in a Boros tempo seat with real two-mana answers, it is not.
