@UncleJimmy hit on a lot of great points. There are so many factors that come into play once a wrestler moves to the next level not just from Indiana but everywhere! You will watch guys that didn't win state titles become all-americans and guys that won mutiple-state titles not make it through their first year or two.
One of the biggest is getting use to there never being any easy days. Most top level guys dominate their room in high school. Once you enter college, especially at the D1 level, you are no longer the alpha and even days you go against walk ons are going to be tough. This becomes mentally taxing and you struggle with confidence issues almost daily!
Relationships with coaches and wrestlers play a part as well. Maybe you don't mesh well with the coaches or the guys on the team. They are partiers and you're not. Another thing I have personally observed is guys fitting in right away and with all the new found freedom don't know how to balance partying, athletics, and school. We'd like to think that these kids can make the right choices but learning how to deal with that freedom can be really difficult! It doesn't make them bad kids it's just the reality.
I was only a walk on at IU. The highlight of my career was being booed at rec hall for stalling and not giving up a major against Pat Cummins when I was thrown in at heavyweight. It was/is still the hardest 4 years of my life physically, mentally and academically. In fact I tried to come home after my first semester and my dad wouldn't let me! It never got easier but it just became the new normal.
I agree with others that this is a good time for Indiana wrestling and we have a lot of talent at many levels.