That's because it's a silly suggestion. An HA already does very minimal damage. It's rare that an HA will get 1vs1 with an opponent and have the chance to pump 6-7 arrows in to the person (that's how much it can take against medium armoured people, 5pd and MW strongbow with bodkins). Most kills are either on light armoured or shots on people who have taken heavy damage.
Removing the Strongbow would simply make getting kills even harder. That extra 3 cut damage makes a big difference. However, I did support the suggestion of adding a 1 slot bow that does slightly more damage than a Strongbow, but cannot be used on horseback. I think that's a good compromise from the foot archers pov (can't remember who suggested it).
As to the manoeuvre/hp argument. Again that has to be taken horse by horse. The Arabian I can agree to that. But horses like the courser actually don't have very good manoeuvrability. If you see an HA moving in tight circles on a courser, it's because they are riding very slowly. In which case you could probably run to catch up to them anyway (their acceleration isn't great). So a flat out manoeuvre/HP exchange won't work.
Also yes...re-adding throwing will help.
There you go...constructive comments for a change