What was the purpose of the higher Specialist ranks?

Back then, the two rank systems were used to distinguish who was a leader (an NCO), and who was a technician (specialists). The higher specialist ranks were given to soldiers who had a great deal of administrative responsibility, but did not necessarily lead any troops. For example, someone who was a quartermaster (supply sergeant) who worked at the Pentagon and worked on massive acquisition projects might hold one of the higher specialist grades. He was paid the same as the NCO of the same grade because of the level of responsibility and expertise he had, but he was not in charge of troops and most of his authority was administrative only.

Just for information:

In 1968 when the Army added the rank of Command Sergeant Major, the specialist ranks at E-8 and E-9 were abolished without anyone ever being promoted to those levels. In 1978 the specialist rank at E-7 was discontinued and in 1985, the specialist ranks at E-5 and E-6 were discontinued.

SPC (Join to see) I was the Chief Fire Direction Computer for a mortar platoon, and was a SP5. I had one subordinate, a SP4 Fire Direction Computer. Mortar squad leaders were all SGTs, perhaps because they had an appropriate number of subordinates, 4 in their case. (Appropriate in that an Infantry Team Leader would also be a SGT and have 4 team members.) By that standard, if you had an entire squad of 10 subordinates, you would be a SSG, and if you had a platoon's worth, you would be an SFC. But if you had less, you could be a SP6 or SP7.

I don't know if this is the ACTUAL reason, but it is what it appeared to be in the early to mid 70's. The only SP7s I saw were senior cooks.

I think then, the Army was trying to increase pay for those who had valued skills, but insufficient subordinates to justify higher rank. I think the Army needs to continue to look into this, and stop the drain of highly qualified talent to the contracting world.