Alright, I'm just gonna spew out a couple of half-formed ideas then.
Perhaps since (at least I think) transsexuals will likely opt not to have children. But they will still generally get jobs and participate in social life and be productive members of society. Because global overpopulation is a problem, having productive members that do not bring another drain on society (excessive childbearing) are a benefit.
Transsexuals will also stimulate the economy (surgeries and hormones are expensive.) Perhaps we are helping the market for such things which, would be more difficult to acquire for those who needed them (supply and demand.)
Perhaps we (just by being different) provide a different outlook on the world. Maybe we encourage others to be more tolerant. Or maybe we're just a medical tool for doctors to discern what can go wrong with fetal development.
In any case, since (I assume) transsexuals are generally not a burden on society any more than any other group, and we may provide some unique benefits/services to our society, we are better to have around than not have around.
Repressing transsexual urges only makes you unhappy, and does not benefit anybody else. I'd say that's enough.
SilverFang