There's a really interesting thing that happens in discussions, I think, where people become exasperated at each other because they are talking at crossed purposes.
When I talk about racism what I mean is the myriad factors that mean that the entire society I live in is based on white supremacist principles. It's the small decisions, organisational and institutional norms; the traditions, practices and principles that bake inequality into almost every facet of social, cultural and political life. In this sense I really mean structural racism - the kind of racism that everyone can (and often will) contribute to without necessarily holding any explicit prejudice in their beliefs. The kind of racism you can contribute to by simply not recognising it exists (and, if you're white, that you benefit from it at the expense of others).
When other people talk about racism they have a much more reductionist view of it. They define it simply as "hating someone because of the colour of their skin" or "acting in a way that is consciously discriminatory due to someone's race." Now, ignoring the argument over which definition is preferable or "right" (because it's the one I use. Everything I think is right. Always). This means that when two people with those two understandings of the word speak to each other they can end up becoming very quickly exasperated with each other because they can't understand where the other one is starting.
Take this thread. There are those that will see Gary Neville's comments as being based in the structural racism that demands different expectations from players of colour, or players from overseas, or players from a religious minority, and want to discuss that issue and unpack the norms that create that situation. Others will read that as an accusation that Neville holds some malicious feeling towards minorities. Crossed wires. Inevitable disagreement.
A good example of this is to ask the question "Is it possible for a white person to experience racism in the UK today?" To me, the answer is obviously no. A white person cannot experience the reality of existing within a society where they are consistently and systematically disadvantaged by their race. They might experience similar discrimination due to class, gender, sexuality, age etc. (intersectionality is complex, y'all!) but the specific experience of structural racism is owned and defined by racial minority groups that suffer due to it. Other people would think of an example where a white person might be discriminated against or even attacked because of their race in the UK and would claim that of course this means that person has experienced racism. They would find my assertion that it's impossible for a white person to experience racism to be basically bizarre and ludicrous. We'd talk at crossed purposes and both end up thinking the other one super weird.
Anyway. Just a thought.