Why weren't they sacked..?

I don’t like or follow cricket, and haven’t done so in over a decade. I read some news during the last world cup that majority of the players were taking bribes and a large number of matches were already fixed.

After reading today’s news about the humiliation Pakistan is going through during the current world cup, it looks like the Pakistani team is comprised of same losers who may have been involved in illicit acts and it almost seems like a repetition - correct me if I am wrong, since I am unaware of the reasons behind the selection of team( such as player’s performance etc). Why wasn’t the team built from grounds up after the last world cup, and why weren’t these players let go..? There ought to be enough talent in the country, when you consider the popularity of the sport? Please educate me on the selection criterion.