I also recall a number of 100+ hour PPL students, of which many or most never finish.
Peter, i reckon i'm going to have about 250 hrs by the time I take my skills test...but I tell you what, I WILL finish!! I did care about the hours it was taking me to go solo, but now I have, I am not bothered about length of time...as long as i'm flying i'm happy!
But I agree with your point about haze. Twice now I have been unable to fly because of it. Although we did go flying in slight haze and the vis was poor for a sector recce and would be even worse for a navex (without a GPS of course!!)