No, it's not. First you made a false claim that barely anyone averaged 40 or more in the 80's. When proven wrong, you claimed that a lot of those batsman barely played a few matches. When shown how many batsman having played 40 matches or more averaged above 40, you increased the criteria of the number of matches to 70 and claimed how just 5 of those batsman averaged over 40, when in fact 7 did.
What you failed to realize is that only 34 players played 70 innings or more in that decade, and 7 out of those 34 batsman averaged 40 or more.
Hence, your statement that barely anyone averaged 40 or more in the 80's using your own criteria of matches played by those players is wrong.