I sometimes watch nascar and enjoy the races, but comparing it to formula 1 is ridiculous.
So you tell me that flying a piston engine plane is harder than a Su27/F15 because there is less technology and then the pilot is a bigger factor?

Technology in F1 cars has always been to make them go
faster and safer, not easier, same as a modern fighter jet.
While nascar is much more "spec" racing, there are still huge differences between teams. From crew, to crew chief to adjustments to engines. If driving skill is the only factor that makes a difference, are you telling me that Jimmie is the only good driver and the others are a bunch a chimps? 5 championships straight!! Schumacher did the same in Formula 1, but the Ferrari of those times was so clearly better it was expected. You have to admit that likely Jimmie's car overall (team) is so much better...
For the car swap of Montoya and Gordon is 2003, you are forgetting a few important details:
The event "tradin paint" was conceived by BMW as publicity of their motorsport involvement. It was scheduled prior to the 2003 US Grand Prix (Indianapolis). BMW was the engine supplier to the Williams F1 team. The Williams drivers were Juan Pablo Montoya and Ralph Schumacher (Schumi Jr, brother of Michael). BMW picked JPM as the driver for the event as Montoya had more ties with the USA (former CART champion) Each driver would drive his own car in a reference lap, then they would swap cars..."trade paint" The USGP is a road course obviously, taking parts of the brickyard oval and a custom made road track in the infield. The reference laps were quite mild by both drivers, as the times by the other were very close to each other. Now, disecting the facts:
Jeff ran a few laps only, but had a heck of a time with the G forces. He was unable to get the HANNS device for proper comfort in the first laps. Even after he did, he was still having a rough time. He only lapped like 15 practice laps, but he was exhausted after the stint. The time run by Jeff in the #24 Dupont was something like 1'37", and JPM's time in the same car was like one second off. The time that JPM ran in the Williams-BMW was like 1'16", and Jeff's time in the same car was also like 1 sec off. Sound impressive by both drivers.... is it really?
The time by Jeff, while very respectable, was 2 seconds off the qualifying time of the slowest car in the grid for the USGP, meaning he would start the race dead last... still sounds impressive for a first timer. But the slowest car in the grid was a Minardi, not a Williams-BMW. Hence, his time has to be compared to the Williams-BMWs. The qualifying times for the race by JPM and RS were slighty lower than 1'12", meaning Jeff's time was almost 5 seconds off! Furthermore, if you are familiar with F1, you already know that qualifying times are slower than race pace, as the amount of fuel on board for the start of the race is the fuel remaining after qualifying (2003 circa, cars get impounded after qualifying) So the cars are heavier at qualifying. Race pace by both Williams-BMWs was in the low 1'10"... I would bet for the exhibition event the fuel load was very low, so times could be even lower and now that makes Jeff's time over 6 second off! We are talking well over 5%. And no, the issue is not talent, Jeff had plenty of talent to drive as fast as Juan Pablo. What no nascar driver has to run competitively in Formula 1 is fitness.
Montoya is probably the most naturally talented driver in the world, but raw talent doesn't make you the best. Execution does. As talented as he is, he is not championship material. He was in contention for the F1 2003 championship, as high as second at some point. What did he do? crash! The last race of the season he was still 10 points behind, mathematically possible... result? DNF! his DNF also cost Williams-BMW the constructors championship. Compare that to the execution of Kimi (9 pts behind Schumi) in that last race. Kimi did what he had to do, press as hard, and had not been for Ruben's (Barrichello) stealing the win Kimi would have won the championship.
Montoya has been closer to win the championship in nascar than he was in formula 1. In 2009 he ended 5th in the final standings, and 4 races into the chase he was 3rd. He ended 5th running in a mediocre car with a mediocre team. In formula 1 his best standing was 3rd in 2003 driving the 2nd fastest car (2003), and 3rd also in 2005 driving the fastest car...
Oh, and just to close the deal, if you are the very best of the best, you want to get rewarded for that driving. More often than not, money gets you the very best. Would you pick the $4 million a season contract, or the $60 million a season contract. The drivers that can command the ridiculous salaries of >$40 mill a season just for driving are surely the best.