STW
Treasury Board: compensation in the private equals compensation in the public sector for the same work. 

Now your other points.
I remembered a 1980 ad in the Globe (you owe $6 billion to the special indexed public service pension plan). The same day an editorial said how unfortunate that only the public sector could afford indexing. You suggest that. I had a look. Two points.

The deficit was due to under funding. The 1980 Actuarial Report shows a cost of 4.7% of salary with 2% of salary being deposited. With indexing looking expensive, the private sector had an excuse not to index. Under funding served a purpose.

Inflation decreases purchasing power. Everyone knows that. Inflation also increases interest rates, thus more money flows into pension accounts compensating for the decrease in purchasing power. The employer has a choice, either index pensions or pocket the money. The media never mentions the increase in interest rates. Nor the under funding. I hope that this helps.