Not everyone deserves a second chance
Second chances are for those who made a mistake due to inexperience (not incompetence) AND want a second try at getting it right. And even then you have to take into account the cost of giving that second chance: is it worth the extra work that others will have to do to make it happen? Is it worth the risk that it won't work better the second time around?
Second chances are expensive and therefore precious - make sure you give them to those who will benefit from them.