^I also dislike Montoya because he was put into NASCAR just for the sake of diversity.
Montoya wasn't "put" into NASCAR. He was on the outs with Ron Dennis at McLaren and he didn't want to drive for a backmarker F1 team. So he called up his old boss, Chip Ganassi, to see if he had a spot for him. All this took place well before the end of the F1 season that year and Daimler-Benz had to broker the deal between their (then) divisions, Chrysler and Mercedes. Chip won the CART championship and the (IRL) Indy 500 with Juan, so he was happy to make room for one of the most accomplished international drivers in the world.
His personality isn't for everyone and it's cool not to like him. But the guy is a former F3000 champion and Monaco winner, and he's won in both Nationwide and Sprint Cup since coming back to the U.S. He's also won the Daytona 24. And with their move to Chevy engines, the Ganassi 42 team has been running up front this season.
It doesn't hurt that Juan is a member of the fastest growing demographic group in the U.S. But Juan is in NASCAR with Ganassi because Chip knows what this guy is all about and he wants to win. And it certainly didn't hurt NASCAR's global image to have a multi race winner from the F1 world come over here. If all that was needed was a Hispanic racing driver, Michel Jourdain, Jr. would have fit the bill... he's even Mexican (whereas Juan is Colombian). But Michel isn't very good in stock cars.