Alegrias1
Just listen to yourselves.
The older generation. She has a point. 
I agree Alegrias1
... haven't any of us been young and idealistic? I know I was.
It's the job of the young to question the status quo, to question the world we are leaving them. It's the world THEY will inhabit.
As for her 'style', yes, she does scowl and remonstrate, but she does have a 'communication' problem and is I believe on the spectrum.
The point is whether she is right - she should not be condemned because she is young... and daring to have an opinion. I bet half the grans on here had one at her age.
It's so easy to be critical of the young, so easy to lump them altogether as 'entitled snowflakes' or slobs who leave litter all over the place. They are, like us, not a homogenous group, and I for one will not take part in this 'youth bashing'. I've met too many nice young people and, frankly, the world they are inheriting is not going to be an easy ride. Let them speak.
... and if anyone is really upset by Greta - they can always simply just not listen to her, or read articles about her. She will make mistakes like the rest of us did (and still do), but she has inspired young people to engage with environmental issues. Good for her.