The one thing I'd like to add (sorry - I'm almost ranting now!) is that, I think, there is something essentially 'post-vernal' about feminism.
In 'post-vernal', I'm trying to find a word that means it comes to fruition slightly late, seemingly anachronistically.
This is, I feel, an effect of discrimination, which erects real barriers in teh lives of real women. Feminist thinking is marginalised: it's not as easy to come across and read and discuss with others as mainstream thinking; it's therefore trickier to develop feminist thinking - as an individual and as a group - certainly when younger; women tend to have other responsibilities, that take time away from developing feminist thinking (and I'm not even thinking about becoming a 'professional feminist', I'm thinking about the fact that there is enormous social pressure on women to 'give time' to lots of social things, and to other people. This may be a good thing [women tend to be more other-oriented and not sollipsistic], it may be a bad thing [women are rarely allowed to get away with 'Oh, that's because he's a genius' behaviour] but it is definitely a thing); women from mid to late life tend to have actual, real caring responsibilities, which massively eats into the time you can spend thinking, exchanging, organising.
So, that's not an exhaustive list, but you can see why feminism itself - with all these impediments - might be 'slow'. These are material factors, impacting on real women, which have an actual, real effect on the development of calls for political change - and the development of activity which might make political change actually come about.
And you can see why individual women might be 'slow' to actually be able to have the time and desire to actually get out there as self-identifying feminists.
And that, I think, is another reason why it's just so crazy to ask 'older feminists' to step aside. 'Older women' may well be old in years lived but may perhaps only just have achieved the personal power to enable them to step forward as feminists. Or to gain a voice as a feminist. Or to have gained a public voice as a feminist.
And the ideas themselves: older feminism. Who can place a temporality - old feminism/new feminism - on a political discourse which, precisely because it is formed to oppose oppressions, exclusions, exploitations and real-life barriers, and which is therefore subject to these very same barriers, etc, itself - on a discourse which is going to have elements which simply take longer to gain a platform? Which are always going to seem anachronisitic?