You keep saying this like it has some bearing on what we're telling you. You keep coming back to chronological age as if it is the ultimate deciding factor, when it's obviously not.
You're 40 and you would "no way" consider a sixteen year old, but would you consider a 25 year old? 20? 30? Is there some hard and fast line you are willing to draw in the sand, never to cross, regardless of how awesome the woman is? I guess we all have our own biases. I've been with someone who was still "underaged" (two years younger than I, but stupid me I ended up marrying him a little later). I've been in a lovely relationship with someone whose age is almost precisely between mine and my mother's, but you would decide based on chronology that loving someone 14 years my senior means I have daddy issues and he's just a horny old goat.
The deciding factor should be the factors to the actual case in question. I haven't seen anyone here say that it's never a crime to sleep with a preteen, teen, etc.. I've seen people try to figure out how automatically assuming there's a crime based on the ages of the people involved has ever helped anyone.
You brought up the example of a 30-something year old and a mid-teen. Most likely, these people met in a school or activities director type setting. The original push for statutory rape laws was about coercion, which is likely to exist in that relationship. The established adult has some kind of leverage over the other person. That's never good, and can easily extend into two adults (or two children, but that's rarer). You don't need to assign each party a number for it to be a crime. On the flipside, I know it's impossible for you to realize this but there IS the possibility that it's a consensual relationship that isn't doomed to "rape" status. It's a very, very slim chance, given the almost non-existent number of wholesome places such a relationship could begin, but it's not utterly unheard of.
If you were her dad, what you're saying is that you'd drag your daughter through an embarrassing and damaging process to put someone behind bars that she doesn't feel has wronged her, all for the "she'll forgive me later" tough love lesson which is actually more likely to leave her damaged, feeling dirty, and always second-guessing her judgement. THEN she'll have daddy issues.
It's seriously as if you're afraid of prosecuting cases based on their individual merits.
A generation is 20 years. 
