it's generally accepted that the liberal bourgeois try to be socially liberal, but they eventually fail at this. The liberal bourgeois, (and by extension the liberal petit-bourgeois and labor aristocracy) often subscribe to identity politics, but ditch those politics once a minority, be that a racial or romantic minority, start to agitate beyond elections or police approved protest. This became apparent during the summer uprisings this year, when BLM bumper-sticker liberals began to call for incrementalism, instead of the direct action of the protests. This is nothing new of course, this has been happening since at least the 1950s.
Bourgeois liberals and their supporters also tend to change from social liberalism to social conservatism when they feel threatened by the collective action of various minorities, this is apparent from Twitter to the national stage, when liberal politicians do not hesitate to send in the troops to quash a protest or when twitter liberals devolve to dogwhistles. To me, it seems that the only thing social liberals consistently believe in is the accumulation of capital, especially through rent-seeking.
There is nuance in all things. No group is a homogenous monolith - the same is true here. The majority of liberals are weathervanes - they act effectively in the way you describe because of:
Sometimes the social liberal faction holds sway, when detrimental material conditions are apparent such as when large numbers are impoverished or during a crisis.
Sometimes it's the social conservative faction like in the aftermath of a terror attack, during geopolitical tensions or otherwise during the manufacturing of consent for war.
Sometimes it's the capitalist absolutist faction - when there are no pressing social issues of concern and business commences as usual in the eternal pursuit of accumulation.
It all contributes ultimately to political pantomime - the reconfiguration of the liberal consciousness to suit any given scenario helps people feel 'stable, secure, sensible' in any given scenario, while the presence of multiple liberal factions emulates ideological plurality without actually presenting people with consequential choice.
It's the ideology of the status quo. Liberalism is capitalist realism, but they think that's a good thing.