Yes it could be done, but it won't.
And here's why:
1. Developers are busy. Free projects are not a priority, but a hobby.
2. Originality. Without it where is the fun? Once you can explain to me why I should create a free app that can do X and is selling for $Z on the Apple Marketplace or $Y on the Android Store. If I'm going to make something it is not going to be a clone.
3. Money, as I said before, we are doing this for free or (at best) donations. Why should I spend hours making something old when I could make something new.
4. This is Indie. Clones are the realm of the big companies that can't spend the time on new innovations, while you may not agree. This is just the way it is.