Thank you, pompa and jane10. Without looking back, the comment(s) I had in mind when I referred to slight hysteria were those of Monty Don. I was particularly surprised at the comments coming from him because I would have expected him to understand how extinction is such an integral part of Life On Earth. Perhaps that expectation was unreasonable. I don't know. On the other hand, I suppose he's an entertainer and a publicist in his field, so that may explain what I regard as the over-emotionality of his comments on ash dieback. I don't see any reason to feel guilty for regarding such comments as over-emotional, nor for saying so in a non-personal way. My remark was not a criticism so much as a realisation. It's not wrong not to know something (in this case, the 'history' of extinctions).
For myself I seek to achieve a completely objective relationship to reality in the natural world. While, being a mere ape, I don't always succeed, it remains my goal.
To get back to ash dieback and beetle infestation, to be honest, if a species cannot defend itself against what the natural world throws at it, then I'm not sure trying to save it by human interference is necessarily the best thing we can do. Please note that I've said I'm not sure. It's never a clear black/white or right/wrong subject. If enough people with the resources and energy to save such a species wants to get together and have a go, then I say good luck to them. Meanwhile it is not wrong of other humans to spend their time and energy trying to defeat pathogens that attack and spoil human lives instead.
So long as we are not the cause of an extinction, getting emotional about the decline of a single species is something I would try to avoid. However, I'm not sure it's automatically right (ethical) to get emotional about an extinction we think we have caused. This is because I believe that, on the whole, human beings are not deliberately trying to be destructive of nature; they are just trying to diminish the effects of what the totally indifferent natural world throws at them and to enhance their own lives as best they can. In short, we are, like all other species, just trying to survive in the best and most comfortable way for us. I do not see that as wrong. And I celebrate that we are the only species, as far as I'm aware, that is now self-consciously trying to help other species survive as well. To have got to that stage is an achievement in human development, not a failure.