Under current rules the 4900 or so covered have to be transsexual not transgender and to be medically assessed by doctors who need to endorse - giving an independent person to come back on if problems result.
Being able to sue a doctor for letting someone inappropriate through is a sensible fall back to guard society.
Around 60/70% of transsexuals do have surgery as it is about sex dysphoria around the body and not gender identity dysphoria (self perceived gender roles) as with transgender.
I think the decision not to impose surgery as a necessity (which I know some transsexuals recommended to the GRA consultation) was partly to do with European human rights and also seems to have been to a degree based on the differing situation in 2004 when passed. As about 5000 transsexuals only who would apply were identified to the government committee. Which proved a very accurate estimate that the government now tell you means the GRA is 'obviously' not working.
In 2004 there were limited surgical options for transsexual men compared to nowadays. And about a quarter of GRC applications come from transsexual men.
I know several transsexuals do argue to impose either SRS or medical evidence (as has recently occurred in Japan in response to changing times) and emphasise why gender self identity is inappropriate as a gateway to the consequences of the GRA.
But as you can imagine the whole self ID ideology of identity is based purely on what you say regardless of any meaningful physical transition or assessment by others and so to them that is unacceptable.
Transgender outnumber transsexuals by at least 30 to 1.
Hence the push to remove all medical and psychiatric checks and balances - coming from the ones who do not have a medical problem but from what I can see often do have more obvious psychiatric problems than most well adjusted transsexuals who have been through that process.
From my contacts many covered by the GRA now feel that the gatekeeping needs strengthening, not removing.
But nobody actually asked those with a GRC before the government created their new ideas. Those were based on the ones who presently did not qualify making demands to be let in. Which explains why they wanted the rules removed, not just adapted.