Public colleges don't teach creationism; they teach evolution. Exposing our children to discredited, pseudo-scientific ideas in the name of "fairness" is nonsensical. There's a reason why every time a creationism bill is proposed in a state, college professors line up to oppose it: They don't want to have to spend time, money, and effort on remedial education for their students in Biology I.
"Equal time" does not apply when the scales are so uneven. When we teach about the Holocaust, we don't give the deniers equal time. When the germ theory of disease is taught, those who believe that sickness is punishment from God aren't given a platform.
The fact is, creationists have had many decades to put forth scientific evidence for their claims and to publish it in peer-reviewed journals. They have been unable to do so. The reason that their ideas have been expelled from the classroom is not a vast conspiracy or rampant hostility toward religion; it's that those ideas lack scientific value.
What's especially sad about this debate is that it is unnecessary. Lots of devoutly religious people accept evolution, seeing it as part of God's plan. We have learned through bitter experience (think Galileo) that when science and religion are forced to fight, neither side wins. That's because these two concepts aren't enemies and weren't meant to fight. Indeed, we all do better when religion and science work as partners to help us understand, interpret, and appreciate our world and humanity's place in it.