Back in 2002 CH would have still been young and pretty small. Ignoring that fact for a moment, even today not every game gets a trainer. There may not have been any demand for it when it was released, and now it's not going to get a trainer a full decade later.
And before you say you pay for a subscription (if you do) so you expect a trainer you want, purchasing a subscription gives you access to the existing and future library of trainers, and also the right to politely request a trainer for a game- a request which CH has no obligation to fulfil by the way. That's all.