High-downforce, drag-limited racing has been part of the Indy racing formula since 1997. One of the big changes in going to the IRL spec in 1997 was a reduction in undertray downforce and an increase in wing-generated downforce. Because wing-generated DF causes more drag, they were looking for a car that created greater drag at the same speed and downforce levels of the previous cars. But, the reduction in hp that came with the original 3.5L NA engines relative to the 2.65L turbos of the cart era resulted in lower top speeds (less HP pushing greater drag leads to slower speeds).
Even with those reductions, it was quickly clear that the cars were going to go too fast to be prudent on the high-banked 1.5 mile tracks. So, the IRL mandated minimum wing angles - not for the downforce but for the greater drag. Instead of putting an upright billboard under a short-cord wing like cart did to slow the cars, IRL put a longer cord wing at an inefficient angle to slow the top speed of the cars. They both accomplished the same thing - limiting top speed through increased drag.
In the early days of the IRL, even into the early Penske/Ganassi movement phase, there were two chassis with different characteristics and two types of engines that were constructed by many more than that engine builders to different team specs. This led to a variety of car capabilities - budget teams asked for bulletproof builds while top teams pushed the envelope more. Thus, there was close racing without the pack racing. The first Charlotte race was as entertaining as any race I have ever attended - cars were spread all over the track, but the lead 3 cars were close to each other and we had what your really want from an oval race - the leaders racing each other through lapped traffic. Really fun, good, oval racing.
It wasn't until Panoz/G-Force left the series and then Chevy and Toyota left the series leaving everything essentially spec - teams' budgets didn't even dictate that there be differences in engine capability - that the real pack racing problem developed. It led to boring racing with close, artificially exciting finishes. Because cars couldn't race to an advantage, fuel strategy and pit work became the only way to differentiate during the race - again, boring.
Good oval racing depends on there being different classes of cars - there must be slow cars to create changing racing environments around the track as the leaders race. Case in point - it is the inability of the leaders to catch the tail of the field and really race through traffic that has made the BY400 so boring lately.
In the end, we know the cars can't run at an unlimited speed on these oval - drivers get hurt, spectators get hurt, and the show is bad. We have been fighting the same problem since Chip Ganassi got hurt at Michigan, since Greg Moore was killed at California, since both series killed spectators at Charlotte and Michigan, and now with Wheldon at LV.
My take, the racing was better in the IRL before the Great Toyota Compromise. I understand politically why the leadership thought it was necessary, but I have not been the same type of fan of the series since that time.