We have the notion that this is our country but we are simply passenger for a very short period. This country belongs to those 16 and 17 who in time will have to give way to the new generations. Phrases like "this youth is lost" has been said for ages and yet the youth is the one that survived and kept the world moving.
They have the longest investment of time in these decisions. I see no reason why they should not have a say in the matter. There was no experience or knowledge requirement for the referendum. Their opinion will not be any worse or better than ours (not 16-17).
This provides a detailed breakdown of what's wrong with the Boris deal content so I'm not sure if this the list you already saw but it certainly raises major concerns in my opinion.