1. Why not? How is that any different than saying their real life arm strength, speed, etc. shouldn't limit them in a Madden Franchise?
2. You don't "deserve" to progress. Progression/ratings are not rewards.
3. How did the worse player perform better than the better one?
4. If your F rated player performs better than your A rated player, who cares what there ratings are. Just play your F rated player. Why do you need the ratings to reflect the production?