Poor advising for residency applications is genuinely one of the things that most adversely affects DOs. I remember people applying and thinking, wow, you really need a back up. Applying to a handful of places even with repeat years or failed classes and then saying they'd only rank 3 or 5. Crazy.
And then there were the ones that were just clueless. I remember in 4th year a student with us that was held back, decided not to even apply for GME, as in not even a TRI, because they "just wanted to open up an OMT clinic" out of their home and didn't want to have to deal with residency. I was like, "but you need at least 1 year of GME for a license, and you can't practice without a license". They had no idea what I was talking about. They genuinely assumed as a 4.5 yr med student that they could just graduate and hang a shingle and that it "wouldn't be a big deal" and could do it without a license. I didn't even know what to say at that point. I tried to explain licensing and, you know, practicing without a license quickly and then just went to see the next patient.