I just wrote an essay reply to this, & lost it.
I read about this & was gobsmacked. I agree with OP, @Alanna1 & @PotholeParadise
The Foreign sec, has shown he is tone deaf, and his innate lack of tact & diplomacy, in a major global crisis on how best to react to the clear & agressive inequalities of treatment of Black & BAME people in society and by many police (worldwide).
The best, he could come up with to go with his placatory words of 'understanding our frustations' was to compare the worldwide protest symbol of 'taking the knee' which he didn't understand, as something coming from Game of Thrones, a book of fantasy. 
Anyway, he is a very mild improvement? on his predeccesor the PM
Nobody insists anyone should take the knee. If you don't want to, don't. But, if he or other posters don't understand the history of 'kneeling or taking the knee' they just need to ask or google it - rather than jump to conclusions as to why protestors are using it as a symbolic stance.
Kneeling.
To God, for prayer, to show respect, honour and yes, maybe subservience (but remember, we are all equal in the eyes of God). In the past you had to be on both knees, now you can just bend down or bow your head, & even closing eyes is optional.
To royalty and the Queen, to show respect, honour (& subservience, if you are a royalist). You may also curtsy, bend or bow, if you are a man. In the past, women did a full curtsy.
In many BAME cultures (speaking for West Africa), you do it to show respect to elders (& husbands in the past) and honour them. Now you don't have to do a full kneeling, just curtsy or bend/bow.
Kneeling for punishment, as a form of discipline.
Single Kneeling on someone, is seen as a sign of oppression and power. It can be in the form of putting a foot on someone's back.
Taking the knee
Takes these in previous statements into consideration and owns the act. Respect to those who are fallen, and honour to those who are suffering and owning the oppressors' stance.
What I also don't understand, this symbolic stance, while it is not new, Colin Kaepernick, the US footballer, introduced a peaceful way of protesting, it is easy to social distant with, it is not permanent like Grafitti, almost anyone can join in, if they want to. But for some people, feel it is inappropriate - is it too peaceful? too simple? too hard to understand?
Yes, there is lots of work to do to make things better for all, not just for BAME people, to improve systems, everyday education (of kids & adults); for 'things' to change/improve constructively.
But Rome was not built in a day; proper debates & discussions are needed, with a wide range of everyday representatives, not governement party appointees, practical solutions needed to aired, agreed, and monitored short & long-term. & no, Serco and the big Audit companies cannot do this task
.
Peace and Love