I will be travelling from Pakistan to Switzerland and then onto Croatia on a Schengen Visa. Can I exit from Croatia to Pakistan directly without reentering a Schengen state?
Why not? Who would stop you? Just make sure to get an exit stamp when leaving Switzerland as it will be helpful to avoid various problems should you come back to the Schengen area or need another Schengen visa later on). Do ask for it at the airport or border checkpoint if necessary. It should happen in any case but I have heard of unusual cases (crossing into Gibraltar, taking a boat…) in which people managed not to get one and had trouble coming back to a Schengen country because of that.