Like I said previously...the L206 is a great engine....and would lend itself nicely to new racers, but I don't think it's the answer for all racers.
Racers like to tinker. They have historically been shade tree mechanics and DIY'ers. There's just not much for the racer to "tinker" with on the L206, and trust me, I work on them on a daily basis as a builder/tuner.
Sure, the L206 is cost effective and reliable. That's appealing, especially to newbies to our sport. The biggest attraction (I think) of the L206 is that it pretty much takes the engine out of the equation -- that is, it places the emphasis on the chassis, tires, and driver, knowing that everyone is fairly equal on power (no new cams, pipes, performance parts, etc. to update with.) By eliminating the engine as part of the equation folks at least feel like they have a better shot at running well.
On dirt, we all know it comes down to tires and that can be a huge expense and learning curve for most. As much as I hate spec "everything," maybe a spec tire would work for new folks. Again, it's proven itself on pavement. The fast guys will still know how to have an advantage even on the same tire, but the perception would be that at least they are on the same brand, compound, etc. they should be able to compete. Again, I'm not a fan of buying sticker tires at the track, assigned tires, impound areas, etc. but I could support it if we saw car counts increase specifically because of it.
Amateur & Pro classes (however you choose to define those) are not the answer. All that does is nearly double the entries for an even later night...with most promoters now insisting that their money racers enter a second class if they want to compete in the pro class. Even if they didn't, the track time is so valuable that the pros would run other classes anyway.
Yet some tracks are successful despite the odds of a newbie winning their class.
I think it really boils down to who provides the best entertainment value for the racer's investment.
If you're at the track all day and all night just to run a handful of laps in one class, you're probably going to find other things to do with your money and time (weekends and all during the week maintenance.) Consider too, if the track doesn't promote a good, clean, family atmosphere, it'll probably not appeal to too many wives, moms (and dads.) Lose Mom's or Wifey's support, and you've lost a lot!
The classes that I see currently most affected with low car counts are the junior classes (at least at the local Saturday night level.) That's a big concern because there's our future. If we lose this generation of racers, it doesn't bode well 15-20 years from now when their generation should be bringing their kids to the track. What's preventing kids from racing? A lot of distractions. From computers and cell phones to video games to soccer, to getting into bigger cars at earlier and earlier ages. There's no doubt that mechanical skills are declining as GenZ ages. That may pose an even bigger threat when it comes time to have our grocery-getters fixed.