I'm guessing it's probably because there isn't enough interest to make them commercially viable and no one has done it just because.
I should also mentioned that some of the sex simulators (not online) have mods that add shemales.
On RPG's: I've just ordered Fable II ofor xbox360 & I'm bidding on ebay for Fable.
When exposed, males rapidly begin a spiral of emotional and physical dependency upon their futa “feeder”.
What’s more, exposure strongly affects intelligence—a male “bound” to a futa in this way is suited for little more than a life of sexual servitude.
In the final product, we plan to have more than ten futa heroines you can interact with, all with very different styles and personality, branching quests, random events, bad ends to avoid, and tons of twisted situations to go through. It turns out Bert was capable of porting the entirety of Futa Dom World from the original codebase (in Game Maker Swahili) to the current engine (Ren'Py) in under three months. It's time for you to hurry up and find love..something close to it.
This universe has spawned, to date, more than a thousand additional captions, an erotic novella, and now, our game. It’s been about four years now since we started working on the game.
If it feels like you're playing an RPG, trying to keep track of everyone's feelings about you and giving out presents, that's a Dating Sim.
First Confirmed Transsexual: I want to play a RPG as a Ts character.In these type of games, you will be looking for a perfect girl/boy and convincing them to go on a date with you.You can even go several times on a date until you are officially with someone.This universe has spawned, to date, more than a thousand additional captions, an erotic novella, and now, our game. It’s been about four years now since we started working on the game. Males are the fairer sex in the Futadom World, and your goal is to choose a character among many, and seduce them...before someone else decides you might be better as a slave.The very first releases will be quite light compared to what we are aiming at. You are a male citizen of the Empire, and as such, you're oppressed and objectified at every turn.It's time for you to hurry up and find love..something close to it.