My addendum --
By the time of The Split, the fatal flaws of CART were already in place. No, not just the fact that the inmates were running the prison, but rather, the decisions that they’d made.
For starters, you can’t have a series where the cars are going 256.99 down the straightaway (MIS, by Paul Tracy). It actually detracts from the race—I was barely able to see a car’s color, much less its sponsor logos—and set the table for their departure from oval racing as well as the 1998 MIS tragedy. And, as Robin pointed out, you can’t have a series which rivals F1 in costs without having the market exposure (and marketing ability) to match. The IRL, CHAMP and to some extent NASCAR have all adopted a common template with either a common engine, or a tightly-regulated engine to address such concerns, but such an idea was completely counter to CART’S religious belief system.
You couldn’t have a series where talented, deserving young American talent is locked out (Jeff Gordon, Tony Stewart, Kenny Irwin, et al). IT wasn’t that all of the drivers were foreigners, it was that a young American had little chance to drive at Indy.
The reason that CART owners didn’t know they were in trouble is that they still had Indy to make them into stars, to attract big sponsors, and to appeal to former F1 drivers. CART didn’t know how much it depended on Indy, even with its fame in other places. By 2001, at the last CART race at MIS (where I had pit credentials), the only drivers that most of the fans knew were the guys who’d raced at Indy—who was these “Tony Cannon” and “Helium Castro” guys? Even though most of that era became the start of the IRL, they only became stars by going to Indy. To separate CART from Indy is akin to American horse racing pulling out of the Kentucky Derby, or endurance racing divorced from Le Mans, or figure skating banned from the Olympics. The owners might’ve disdained the partying owner’s son at IMS, but little did they realize that he held the only trump card in the entire card game. The US 500 in 1996—heavily supported by Toyota, who paid fans to attend—signaled the height of their arrogance, and the beginning of the end.