Why, exactly? What good would that do?
The problem is not the seeding, climate, weather or whatever you want to use as an excuse. Modern football is simply poor and National teams reflects that. You want to tell me that Southern Italian, Portuguese and Spanish people can't stand a little heat? Get out of here.
Their summers are just as hot. They are just bad teams, just like Brazil, Argentina and Uruguay. An older friend of mine who's seen Pelé, Cruyff and other legends in their prime told me something that i found to be very true; He said football has it's bar set so low that all teams are equal now. That's exactly what we're seeing.