He's saying dozens of people have explained why no one drafted him...even in the 7th round.
It is possible that a team could have drafted him in the...5th-7th round, but like he said that would give Collins the option to enter the 2016 draft.
My question: If you were Collins and got drafted in the later rounds by a team willing to take a chance, would you train all year long or say F it and get your NFL career started (assuming that the team that drafted you gave you a real chance to start)?
Edit: I don't know enough to speak for someone actually in that situation but I would imagine that if I were in that situation I would be tempted to move on with my life and start competing in the NFL. Especially if the Bills drafted me