How doesn’t the SC defend our rights?

In the case A and others v Secretary of State for the Home Department (2004), the Law Lords declared that the indefinite detention of suspected terrorists at Belmarsh prison was incompatible with Article 14 of the ECHR because the Act discriminated against non-British citizens.
In response, the government introduced the Prevention of Terrorism Act (2005), which replaced the discriminatory detention of foreign nationals with ‘control orders’, applicable to British and foreign terror suspects.
Following the ruling in HM Treasury v Ahmed and Others (2010), the government introduced the Terrorist Asset Freezing Act (2010), to give them the anti-terrorism powers the judges found they lacked.
While the judiciary can rule that government has acted beyond its powers, it cannot prevent Parliament from passing laws that gives officials the powers they previous lacked.

Brexit will not prevent cases being taken to the ECHR, but repeal of the HRA might render ECHR decisions less effective and the UK will not be bound by changes to EU law.
Following the 2016 EU referendum, the Government proposed a Great Repeal Bill, which would repeal the European Communities Act, and transpose all existing EU legislation into UK law. UK courts would be unable to prevent Parliament from amending or repealing any of the rights and liberties that are carried over. While politically challenging, it is equally possible for Parliament to repeal the HRA, which would obviously further limit the courts.

Arguably doesn’t protect everyone’s rights as it lacks diversity.
The main argument is that judges have come from a narrow social and professional background. The majority are from middle and upper-class families.
They are almost exclusively male, and the majority have been educated at independent schools. Up to the 1990’s there was good deal of evidence to suggest the background of judges did affect their outlook.
There were consistent decisions in favour of the government over trade union rights and policing powers.
In addition, the first Supreme Court which began in 2009 had 11/12 of its members educated at Oxford or Cambridge. Only 1 was female, and the average age was 68. Overall, it looked very Conservative.
The social composition has changed slightly, bringing in independent-minded, ‘liberal’ judges to senior positions e.g Lord Hoffman. Finally, these individuals have received criticisms from both main parties suggesting they are largely neutral.