I think the poll is wrong.
In 3e, the con effect is constant. (not slightly increasing).
It is only slightly increasing if you use the approach of maximum hit points at first level and constant hit points (1/2 or 1/2 plus 1) at level 2+.
If you are rolling hit dice at each level, then con effect remains the same for all levels.
Also, in AD&D, many people rolled hit dice and added con at high levels, and ignored the +1/+2/+3 hit points per level at high level.
In AD&D through 3.5, a fighter's two most important stats were STR (offense) and Con (defense) with dex a distant third. In 4e, con became essentially useless for fighters (only giving a bonus to hp at 1st level), and allowing fighters to use str for fort saves. 4e fixed the toughness feat though, so a 4e fighter should take toughness whereas a 3e fighter avoided toughness (3hp.)