When people fail to reply to what I actually post, making accusations about me instead, it makes the discussion about me.

Only if you let it, Keith. It takes two to tango and, if I may use another platitude, it doesn't matter who started it; it is whoever stopped it that counts.

Why not criticise them for making the accusations, instead of me for defending myself?

I am not criticising anyone for making accusations or defending themselves. I am criticising your style of argument. I find it very irritating. Whether you take any notice of that opinion or not is entirely up to you.