NASCARS are scratch built, thats the biggest difference compared to Touring cars. I used to enjoy NASCAR, but since most all of the old school stock car racers left it lost its appeal.
Whats to enjoy in watching cars go round in a circle? They cover a greater distance (Petit LeMans notwithstanding) at a higher speed, and often overtake and get overtaken more than once on a lap (unlike F1 where overtaking a car is a big deal). Crashing is to be expected, especially at the 1/2 mile tracks and Talladega. The cars often touch and nudge each other, and on the restrictor plate races they bump-draft up at 200mph. Sometimes there's a punch up in the pits (sometimes between whole pit crews). Often the drivers talk to the commentators while they're driving. In car cameras (usually 10 in each car) get up close and personal and you can get real time telemetry data with it (which I love). Aaand so on ...