Ron, you didn't read it wrong.
The suspension on the bike has two purposes - and neither of them are to make the bike ride smoother on the track for your comfort or convenience.
First and foremost, the suspension is mainly focused on managing leverage, mass, etc to allow the tires to have consistent and maximum performance relative to the track surface. While you're negotiating braking, turns, imperfections in the track, etc - you want to minimize the sidewall deflection and distortion of the tires to allow for a smooth consistent contact patch between the tire and the track. The second thing (which is related) is to create the optimal geometry in terms of front fork rake, etc (by compression of the forks and therefore shortening them) to manage the compromise between agility and stability. Agility at turn-in, and stability on exit just to generalize. (an Edit here: When I say minimize the sidewall deflection and distortion, I really meant minimize changes once you've set the contact patch, and maintaining the RIGHT deflection. You DO want to deflect that sidewall to allow for a larger contact patch - you just want to smoothly create that larger patch and then maintain it until you're smoothly on the gas at or just after the apex to the exit - rather than crushing it, releasing it, and changing it again)
Just like how as you start on the track, you can drop seconds per lap as a result of better technique, but the faster you get it becomes harder and harder, and you're fighting for tenths of a second per lap - suspension is similar. Ignoring rear wheel traction in a straight line for a moment - as you start out suspension that's just in the right ballpark in terms of spring rate is usually more than enough, but as you begin to improve your technique and be more aggressive on trail braking (or braking in general), and exits, the more accurate that suspension should be and the more difference you'll see - particularly with tire wear.
Front and rear springs set the overall range that you can adjust the suspension. You can't exceed via valving, rebound, preload or compression what the spring itself can do. You can only fine tune in the range of that spring.
Let's make it simple. For probably most track riders - certainly everybody in N group and probably most people at least in I group to start with, OEM suspension on modern bikes with correct springs and adjustment is more than good enough. If you're 160lbs, OEM springs are good enough. The harder you ride, and the bigger you are, the more likely it is IMHO that you'll see any need for the fancy stuff - saying this even though myself and most of my friends all have the fancy stuff. But without the spring rate being in the right ballpark, what can happen is that you run out of suspension, and the sidewall of your tire becomes your suspension. A set of springs is pretty inexpensive - you'll probably save that price in rear tires alone.
