Hinduism, Buddhism, and Jainism are based on diversity, which is often misread as inequality. Every human being is different, because we all carry different karmic burdens from our previous lives. Each one has different strengths and weaknesses, opportunities, and threats. So, one rule cannot apply to all
This is just a defence of casteism here. One belief is that people who have good Karma are reborn as Brahmins and those with bad karma are reborn in the "lower" castes. Thus they can justify casteism since those in lower castes deserve it by being evil in the previous birth.
You are correct that the thousands of beliefs and sects under Hinduism cannot all be tarred in the same brush as casteist but that specific quote is definitely a nod towards casteism and discrimination against disabled people.