From a moral perspective, a government has a duty of care towards its citizens and the importing of people with life changing, non-curable diseases is a failure of that duty.
The United Kingdom, despite being almost forty times smaller than the United States, will approve twenty-five times as much permanent residency applications from India by 2026 onwards.
Under the current system, a man who cannot hold a fluent conversation in English, who has no ties to the UK other than a residence period, who is a nuisance to the local community, and who has never been a net taxpayer can receive a British passport.
If a nation applies restrictions against British citizens in its realm, then there should be restrictions against their citizens in the United Kingdom.