Why does she never attend award shows?

I don't think awards really matter to her anymore, if they ever did, though I imagine is flattered and delighted to receive them. But I think at her age, she doesn't want to travel to and forth from the States to attend them. Additionally perhaps they are scheduled when she is working and therefore her attending would be difficult. For instance at the EMMYs last year she was filming My Old Lady in Paris, this year she'll be filming Lady in the Van..... In Jan/Feb this year she was in India filming Best Exotic Sequel so she couldn't attend!
I am sure if she nominated for a BAFTA she would attend!
She is apparently attending the Toronto Film Festival to promote My Old Lady....

Even when she was younger she didn't really attend. She wasn't there for her win for Jean Brodie, Travels with my Aunt and A Room with a View. She did however go for California Suite which she won!

Quite right. She has attended the Oscars only twice (1978 and 2001, although she did present awards in 1970 and 1977), the Golben Globes once (2001) and the Emmys never.

After attending the 1978 Oscars (and winning for California Suite) she has had an intense dislike for award shows and attended the 2001 Oscars and Golden Globes only to promote Gosford Park as a favour to Robert Altman.

The truth is neither here nor there. It's the look of the thing that matters!

She was working on stage in London when she was nominated in 1970, 1973 and 1987.

She also attended the BAFTA's in 1993 when she was awarded her special lifetime award and again in 2000 when she won for Tea with Mussolini.

She also attended the Oscars in 2002 when she was nominated for Gosford Park.

(I love spoilers so go ahead and tell me everything.)

After attending the 1978 Oscars (and winning for California Suite) she has had an intense dislike for award shows With all due respect, perhaps you are misinterpreting her history. Because the way you tell it makes it seem as though her Oscar win in '78 was a bad experience, which caused her to dislike award shows. But, when watching clips of her interviews at the time, I see no indication that she wasn't mightily happy to be there. On the contrary, she seemed very humbled and pleased to be there. So, if anything, it seems like her decision would be to keep going because her experience was good. Otherwise, her decision to hardly attend those shows is probably completely unrelated to her experience of them.

Has she ever said that her 1978 Oscar experience was an unfavorable one to her? What gives you the idea that her lack of attendance links back to that time (since she has always been scarce in that regard anyway)?

Please excuse typos/funny wording; I use speech-recognition that doesn't always recognize!

I've never read that she disliked going to award shows either and she even stayed in Los Angeles longer than planned after she won her second Oscar, saying she wanted to 'enjoy the feeling of being a winner'. As much as she adored Robert Altman, that award season I doubt she would have gone to the Golden Globes, Oscars, and presented at the Oscars just because of him.