Was a point system implemented to train pilots to land on aircraft carriers?
Early on in US Naval Aviation, the system began to assign a series of grades for landing performance and set minimum grade requirements to carrier qual and manintain proficiency for naval aviators assigned to carrier based fixed wing squadrons.  The reasoning was to weed out aviators who could not maintain these standards, thus preventing a lot of accidents aboard ship.

A fixed wing carrier pattern and landing has quite a bit in common with that found in terrestrial flying.  However due to the small landing area aboard the ship, the tolerances are considerably tighter and the procedure is more demanding on the aviator.  The Navy found that unless strict standards were adhered to, pilots would begin to lax in their performance and begin to develop bad habits with their flying which could degenerate into dangerous situations.  Therefore all landings aboard ship are now graded by a team of Landing Signal Officers (LSOs).  LSOs are experienced naval aviators who have undergone additional training and experience to become an LSO.  The LSO observes the aviator in the pattern and monitors the pilot’s progress to make sure they’re in the correct position, altitude, airspeed and AoA.  Specific position in the pattern and final approach are graded:


Abeam the platform: the Jet should be abeam the LSO platform on the downwind leg of the pattern, approx 1 mile offset from the port side of the ship, at 600 ft ASL, at a target pattern airspeed, in the landing configuration.
At the 90: the jet should be halfway through the left turn to final approach, perpendicular to the direction the carrier is steaming, about 1 1/2 miles behind the ship, 450 ft AGL, at optimal AoA.
A
Crossing the Wake:  the jet should cross the ship’s wake about a mile behind the ship, 450 ft AGL, at optimal AoA
At the Start: the jet should be lined up in the groove - landing area centerline - and on glideslope - call the ball - about 3/4 mile behind the ship at 450 ft ASL, at optimal AoA.  Major deviations from AoA, lineup and glideslope should be corrected at this point or a go-around should be executed.
In the Middle: in the groove, on glideslope, on AoA.  Any minor deviations should be corrected here. Overshoots and worsening deviations from these targets should require a waveoff.
In close: the jet is 1/4 mile from touchdown, on glideslope, in the groove and very very small corrections being made to maintain these metrics.  Probably the last safe chance for a waveoff, if needed.
At the Ramp:  jet is over the roundout, on glideslope, on groove.  LSO may give the cut signal for the pilot to pull power to idle, if high, but not unsaveable high.
In the Wires: jet touches down (impacts) the deck on the main gear between the #2 and #3 cross deck pendants.  Hook snags the #3 cross deck pendant.  Pilot goes to full power in case of bolter or hook skip and makes ready to go around.
Final Stop: jet comes to a halt in the LA on centerline.  Power to idle.  Disengage the hook from the cross deck pendant.


These positions and metrics are graded and a composite score is released by the LSOs on the platform.  Grades are as follows.


OK Underline:  Superlative pass at the boat conducted with additional complications eg engine failure, barricade landing, etc.  Worth 5 points.
OK “Oh-Kay”: The highest score achievable under standard conditions.  Jet flew pattern and approach with minimal deviations, all promptly corrected for.  Hook snagged the 3-wire.  Good pass worth 4 points.
(OK) “Fair”: A fair pass.  Flying was good but there were a few deviations.  But overall, solid and safe.  Worth 3 points.
OK-Bolter:  a solid and safe pass but hook did not snag a cross deck pendant.  Worth 2.5 points.
No Grade: Too many deviations.  Described by LSOs as “ugly but safe ugly”.  Ironically worth 2 points.
Cut Pass: Unsafe attempt.  Gross deviations outside of the safe margain for flying.  Consider yourself lucky to walk away from this one with only the LSO’s teeth marks in your hinder.  Worth zero points.


A typical review of a pass may read something like.

202 (Jar-Jar): Slightly wide abeam, High at the 90, high and left at the start, slightly high in close, OK.

Squadrons have certain minimum landing GPAs and boarding rates (ratio of traps to total landing passes).  An F-18 squadron might require a GPA of 2.75 with a 60% boarding rate, etc. to remain carrier qualed.

PERSONAL OPINION

I think that grading began as a means of leveraging the competitive nature of the aircrews to motivate better performance.  Again the tolerance between an OK pass and a No Grade are pretty tight compared with landing on terrestrial runways.  Sloppiness can start to creep in unless drilled out.  3-wires start to become 2-wires, then 1-wires, then taxi 1-wires and finally rampstrikes happen and people get killed.  Landing grades are posted in the squadron ready rooms and everyone wants top spot.  If you screw up, everyone’s gonna see it - and it has a serious meaning.