http://runescape.wikia.com/wiki/Chaotic_equipment
http://runescape.wikia.com/wiki/Gravite_equipment
But if you're going to limit defense in this, limiting prayer would also make sense. No point in getting higher prayer than 52 (45 tbh anymore) without turmoil, but people still get higher.
The pure world has never had a major issue with limiting prayer, or even attack for that matter. The point of being a pure WAS to be the highest offensive threat with the lowest combat. This wouldn't include any extra prayer(52 prayer would of been max), and would definitely not include any extra attack (80 atm for chaotic, 75 before then for gs, etc, etc).
Classic - Pure was 40 attack, 1 defense, high strength, with r2h. You could raise range, whatever, but to be the at wildy, you use the above set up, because it was simply the best.
Beginning of RS2 - With the introduction of such things as weapon speeds, people started range 2h'ing with 1 defense to be "pure".
However, as RS2 developed, with the introduction of fremmy helms in 2004, and other OFFENSIVE bonus ARMOR, people started to change how they pked. It became, pures would fight pures, over time. Reason being is that with the more armor that came out, pures who wanted to compete with mains in 1v1, were forced to take sacrifices if they wanted too. And in recent years, it has been piled onto the pure community.
The point being made is that if you want to compete with mains, that is your choice. You can choose to get defense and get turmoil, corrupt armor, handcannon, void, etc, etc, and compete with those mains. If you don't want to do it, then you compete with pures like yourself, who aren't willing to move on simply because they're following tradition passed on by everyone who followed in the original pures footsteps.