Nobody is "forcing" you to do anything. You are choosing to dodge. Just how if you're driving dangerously and you have to swerve because you don't leave enough room in front of you, and you happen to hit someone else in doing so, that's your fault, not anyone else's.
It doesn't have to be a "pocket pick". People are allowed to play the champions they desire to play. Smite in bot lane has become even more appropriate now that dragon is such a contested objective. Cleanse is more than appropriate as a summoner spell and honestly I'm not sure why more people don't consider it over flash and/or heal in a lane where CC is the biggest issue. Tristana is even better with cleanse because she could potentially cleanse a CC then immediately jump away - saving her life. That makes it much more efficient than flash which would not be usable during CC and she may get bursted during the CC.
Tristana as a support is also a zoning support as well as a disengage support. Her range increasing throughout the game allows her to consistently be poking the enemy off their minions, her explosive charge doing the same by causing the enemy to take damage if they are near units she places it on, and her ultimate allows her to knockback enemies to save her bot laner in a quick disengage.
So yes, she functions as a support if the player wants to play her that way. You do not have the right to tell others what they can and cannot play. As such, Riot will not be removing punishment for you leaving the game becuase you are not authorized to do so simply because you disagree with a teammate's choice.
