Stop using people with disabilities as your shield. It's disrespectful to those who actually have them. And those who do have them have been able to complete the quest just fine.
By OP's logic, EVERY game, sport, event, or task that cannot be performed by every person is discriminatory.
If you can't dunk a basketball, then basketball discriminates against you.
If you can't beat God of War, then, obviously it's discrimination.
If you failed your math test, discrimination.
[u]Being bad at things is not discrimination[/u]. I don't think you know what that word really means.