I would think kids are easily able to graduate in 4 years now with all the dual credit and AP classes. My daughter and her friend just graduated in 3. My son just entered his freshman year as a sophomore due to dual credit, as did most of his friends.
not sure how out of date this is but many moons ago, I started college at a small private university. there, your path to graduation was set and, as long as you kept passing classes or didn't double or triple major, finishing in 4 years was easily accomplished.
then, I got hurt, couldn't play ball any more and transferred to a large public university. There, they couldn't care less about how long it took you to graduate. you were just a number and, if you got your classes, you were good but if you didn't, you were screwed.
if it's anything similar now, i'd think the majority of the D3 guys can more easily finish on time so the decision to take advantage of the extra eligibility comes down to whether spending the extra tuition is worth it (or grad school/extra major/minor, etc).