You failed to take into consideration how man Critical hits you actually had on each parse.

I have a Dragoon in my group who has gotten lucky, and dealt more damage with a very sub optimal rotation just due to crits vs the most logical, and highest potency rotation for the same time period.

Re-parse, and add in how many times you crit in each one, and you will see why the numbers are so different.

The fact that more strength consistently added damage still shows that even with the overall chance of bad damage rolls and bad Crit rolls, you STILL can pump out a significant difference in DPS with minor upgrades to the stat.