You're missing the point. The idea is that points from heroics put you 1-2 tiers below the current normal mode (2-3 tiers below current heroic mode), so that somebody could actually get into raiding with a character.
The way you suggest basically means that nobody would ever realistically get into raiding if they joined after the first few content patches, because they would have to farm outdated content to try and catch up with others. Think about that