I am not sure I get the reason why Hard 100% isn't "respected", tough.
As a speedrunning category, nobody takes hard mode seriously for the prime series. This is because the only real change is the damage you take/deal, which isn't really enough to warrant making it a serious category for most people. As Themg2 mentioned, the only metroid game where hard mode is taken seriously is:
- Zero Mission. Not only do you take double damage, but a lot of enemy layouts are different, some save rooms are flat out gone, boss PATTERNS are changed, and you get about half ammo/health per upgrade, making hard any% significantly different from normal any%. Keep in mind, 100% hard isn't ran seriously for even zero mission because it's largely the same as normal 100%, except for basically making a detour to refill in a save room every 30 seconds in chozodia thanks to one power bomb per tank rather than two.
- Other M. You get absolutely no upgrades at all since they're all removed in hard mode. This actually changes combat significantly, from my understanding, but it's best to ask jaggerg/angelix about this. But keep in mind, this isn't really equivalent to hard mode in the prime games, as hard mode in other m doesn't change anything besides removing upgrades, basically making it a forced 0% category.
Also note that hard low% is sometimes done as a challenge, not as an optimized speed category. These are different.
- Zero Mission. Not only do you take double damage, but a lot of enemy layouts are different, some save rooms are flat out gone, boss PATTERNS are changed, and you get about half ammo/health per upgrade, making hard any% significantly different from normal any%. Keep in mind, 100% hard isn't ran seriously for even zero mission because it's largely the same as normal 100%, except for basically making a detour to refill in a save room every 30 seconds in chozodia thanks to one power bomb per tank rather than two.
- Other M. You get absolutely no upgrades at all since they're all removed in hard mode. This actually changes combat significantly, from my understanding, but it's best to ask jaggerg/angelix about this. But keep in mind, this isn't really equivalent to hard mode in the prime games, as hard mode in other m doesn't change anything besides removing upgrades, basically making it a forced 0% category.
Also note that hard low% is sometimes done as a challenge, not as an optimized speed category. These are different.