"when you watch the nine minutes of Geo Floyd dying - you feel exactly the same thing ?"
What has that to do with the UK and it's citizens ? Governments can officially protest, but interest groups using it as an excuse to cause trouble in a different country, and disharmony between parts of it's society, that otherwise get on, is unacceptable. Slogans implying only certain lives matter and making a show of supporting this anarchy by going down on one knee, or railing against statues and damaging them, none of this is the slightest bit acceptable. And hardly surprisingly, it results in counter behaviour by those who then feel they are under attack: which may be part of the aim. Cause friction, cause conflict, manipulate the less mentally strong to get them to rise up against the majority decent citizens.