You're right this isn't Nascar, F1 or autocross. The only time attack that I've heard of that actually uses a factoring system is OTA. There's maybe more but the majority of time attack events that I've seen have regulated classes that compete raw time.
Why do we need to "properly prepare" a car for its class if pax is supposed to be the great equalizer?
We've all seen numerous flaws in the pax system so I would disagree with the statement "all is equal".
I understand everyone has a different budget and it's important that those with a lower budget still have a chance at winning. I think with good regulations and classes there can be room for modifications that improve lap time. With a limit of course, too many modifications would bump you into the next class. This makes the slower classes more favorable to lower budgets. We all know that racing isn't cheap and it's definitely not free. If there are "enthusiasts that don't feel the need or have the ability to put any money into a vehicle" i personally don't think that's how you win a championship in time attack. I don't think they should be "penalized" but I think it should be acceptable to allow some modifications within a class.