You're right that some black officers feel discriminated against, it sadly happens in many workplaces yet that is the fault of racist officers/colleagues and not the organisation as a whole. Those individuals deserve to face disciplinary action, I don't think there's any debate about that.
However there are lots of 'stories' from some black officers, some completely valid yet others which don't make a great deal of sense. I'm namely thinking of
this story which is a fairly typical one - a number of former BAME senior officers (who have been promoted to the 'top brass') retire, run to the press then accuse the service of racism. If the organisation was so racist, why would they promote BAME officers, and why not raise the issue when in a position of influence?
Leroy Logan is quite a prominent character, who has called the Met out for being racist. He is black, yet was also promoted and retired as a Superintendent following a 30-year career. He was chair of the Black Police Association and had every opportunity to challenge alleged racism in the service. I don't want to use the bandwagon fallacy but you do have to question why he and many others bring these issues up and drag the service through tribunal proceedings many years after they leave. The Professional Standards Department deal with any allegations of racism at all ranks between officers, and rest assured they act decisively often to avoid tribunals and costs.
I genuinely don't belive officers worry about the colour of their colleague's skin - they're all united in service and all have each other's backs when things kick off. Of course racism still exists, and should be called out internally, but the problem is by no means as endemic as many are led to believe.
In terms of racial tensions between the Met and a certain section of Londoners, there's no doubt relations between the police and public has deteriorated in recent years. I personally put that down to social media, and the growing distribution of videos or allegations which give a fairly short snapshot of an incident - a Met chief
has spoken about this and criticised the growing trend. People can write what they like on Twitter, completely unvalidated and unfounded yet it is shared thousands of times. That leads to an untrue perception of the police, to which they are often unable to hit back at.
It's a well-used fact that black people are 5x more likely to be the victim of a violent crime (homicides) and 8x more likely to be the perpetrator in London. As a result the Met stop more black people, which some find controversial. The allegations of 'institutional racism' are simply fiction on that front - people expect the ethnic make-up of stops to be exactly proportionate to the ethnic make-up of the area which doesn't reflect crime trends. If young black males are statistically the typical victim and perpetrator, it's mindless to not stop young black males in pursuit of eliminating violent crime.
'Institutional racism' is a phrase used far too often, often by disgruntled members of the anti-police parade who may oppose a particular action or decision which to many is completely justifiable.