The donuts are good, the coffee is weak AF and it's hard to find anyone who "loves" it. If they do, they probably take it double cream (18%!!) and double sugar, which is basically coffee-tinged hot ice cream. I think Al's beef is probably the fact that there is a weird cult of nationalistic pride surrounding Tim Horton's, where the brand is supposed to be seen as some kind of badge of honour for Canadians, and it's seen as unpatriotic to look down on the brand. It's just this sort of trashy, ubiquitous thing that we are supposed to accept and embrace, when really their prepared food is all very un-fresh and their coffee is shite.
They have also cornered the market on hockey cross-advertising in this country to a somewhat uncomfortable degree.