They offer degrees for which the graduate must be knowledgeable of evolution in order to be seen as competent in their field, and also other parts of the the related scientific curriculum relies on it. It's not taught because they believe in it (though individuals probably do, being scientists) but because it's the accepted scientific theory.
Well it's hard to tell if their knowledge of evolution is why they left the church. Almost no one I attended MBA and PUC with in the 1980's is still an Adventist, and none of them because of La Sierra's curriculum.
However, I have often stated that if you learn something new and it causes you to question your faith, that is a good thing. If the answer is that your faith has failed you, then your faith was perhaps based on lack of knowledge or false information:
If your faith hangs on the idea that the world is the center of the created universe, as was taught by the church before Galileo (and for some time after), and the knowledge that the universe is actually infinite (as far as we can tell) causes you to lose your faith, then so be it.
This is actually exactly what the church was afraid would happen when they castigated Galileo, as they had taught false science for centuries, taught that the earth was the center of the cosmos, based on their interpretation of the bible. They feared that the new knowledge would bring a crisis of faith upon the church.
For me, this history should give modern churches pause, as they too insist on teachings that belong in the realm of science, though they have little to no basis for those teachings except their interpretations of the bible, and those teachings actively disagree with scientific facts.
I think some people in our church, in this WO battle, need to remember...
It is important to not confuse this:
Remember the difference: "The Church" can refer to members of the body of Christ, which is the people, or to the corporate entity that exists to serve them, to facilitate their belief.
When that corporation starts dictating how the members should practice and believe, instead of reflecting how the people want to practice their belief based on their convictions, there is something wrong.