Taunting Bloon is not a strong option, however some players may apply health-buffing sources (e.g. Improved Fortification and Booster Bloon), as well as healing sources once they're health-buffed, to prevent the opponent from targeting other Bloons for a long time.
Note that health buffs can increase max health of a Bloon, which is why heals can set health above the Bloon's health when first played.
Return to Sender is a common option against that type of strategy, since a lot of Gold would've been invested in the first place; the opponent would lack aggression without it.
Low-damage 1 reload Monkeys shouldn't have much trouble against Taunting Bloons without buffs, but this can be effective against high-damage Monkeys with longer reload, such as Bomb Shooter.
For the cost, it's outclassed by Target Practice Blimp, due to Taunting Bloon's high cost per Bloon, despite increased charges. Additionally, Mountain Obyn's Sentinel Bloons fulfill a similar role but better; they don't cost card slots, they can drain the opponent's lives quicker and easier, and can use similar synergies to keep them on the board.
Spike Storm! is an easy way to stop a swarm of unbuffed Taunting Bloons. Likewise is Mountain Obyn's Brambles.
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