You just explained why it makes sense to clone Ada and not the mains characters of RE.
You see, it would make more sense to clone worthless people (that not a lot of folk care about), than to start cloning really important people.
That's why presently, real cloning is limited to sheep and other lesser lifeforms. And why they didn't start with Jesus. Because if they started with him... well... LOL, well you'll get a much worse reaction from his fans, than the reaction RE fans would show if suddenly Wesker, Chris, Jill, Leon, Claire and other main characters started getting clones. But both fanbases would absolutely hate the idea.
But cloning a small-time character? No big deal.
Well thats not the case at all I guarntee you that Ada wasnt the first clone ever it would have been some civilian that nobody knows so they had to use someone we know so that we recognise them and it has more of a shock value. But in my opinion the only people who are going to give a toss are fans of Ada. My point is Ada is a pretty lame character to pull this crap with, anyway its pointless going on about it clearly we dont agree so thats your opinion vs mine.