This. It’s a facile gesture
Individually, it might appear a facile gesture, i agree. However, over time, educated parents of bright children choosing to send their children to a comprehensive even where a grammar is available - both geographically and in terms of ability - DO change the public perception of such comprehensives.
Some of the reasons parents give for NOT sending their children to comprehensives when a grammar is available is are:
'They need to be with similar ability peers in order to thrive'
'There isn't anyone at the comprehensive who gets the kind of results I expect my child to get'
'They don't send any pupils to the kind of university I expect my child to go to'
If people like me do send their bright children to comprehensives - and in my area I am part of a large group, following the lead set long ago by those who gradually changed the profile of the school from 'a true secondary modern' to 'a true comprehensive', then those children form a peer group, get those grades, enter those universities (because the school is good, but historically its intake was skewed towards lower ability students) and other similar students follow them.
I wish i could claim to be a local renegade, a trailblazer, a moral crusader - but actually, round here I am deeply normal, really just following in the tracks of, and helping to secure the ethos set by, those trailblazers years ago.