Stop trying to act like they are a 12 year old kid that can't make up their mind of what flavor tootsie roll they want. A 17 or 18 year old is fully capable capable of making a decision and being held accountable. There is a reason why there is a difference between a verbal and a written commitment. The verbal still gives them time to really make sure, we do not want any players who does not want to be here.
A 17 or 18 year old can enlist in the armed services and go fight our wars, they will be held accountable if they commit a crime, they can get married (I did at 18), etc.
Of course it is a hard decision, but so are many other things that you have to do in life. Live is made up of living with your decisions and understanding the consequences. People are counting on them to live up to their word of playing hard, going to class, giving their all, working out, staying out of trouble, etc... It is more than just saying they are going to a specific school.