That is your opinion on that then, I am the complete opposite and love it more if the girl initiates it herself, being forced/blackmailed has gotten to be one of the most overused tropes in NTR doujins in games so it doesn't even surprise me anymore nor is it well thought out. I think my optimal story setup would be if the girl is being romanced by the antagonist so it becomes more or less an actual rivalry, there are few games/stories of such nature but one good example of that is
You must be registered to see the links
At the end of the day we all have our own preferences and I don't see one being objectively better than the other, but I do see an increase of authors really milk that 1blackmail trope to have an easy access to NTR fans budgets which pisses me off.