Calling us conservative or right wing is a way to other us, to kick us out of the tribe. It's purification. See the endless torrent of hate being directed at Bill Maher lately for maintaining liberal values. I've seen it hundreds of times on Twitter, "I'm so done with him! He's not one of us."
Your reaction to it springs from a lack of knowledge about it. Calling the difference "1 or 2 policies" is reductive and ignorant.
To wit: someone who calls themselves a classical liberal is doing the same thing other people do when they tell you their pronouns.
So I suspect your observation about the "last few years" is more a reflection of the evolution of your specific info-environment, & rhetoric consumption, than a broader trend.
For example, Google books show it rising from nothing before the 1930s 'New Deal' era (of massive new government economic interventions), to a steep growth in the 1980s (Reaganism etc), starting to plateau in the 20X0s:
https://books.google.com/ngrams/graph?content=classical+libe...
Search trends show interest in finding out what it is roughly stable since 2004:
https://trends.google.com/trends/explore?date=all&geo=US&q=%...
In the late 1800s, 'liberal' overwhelmingly meant in favor of free trade, less government involvement in running or regulating private enterprises, & free speech – not especially "liberal" policies in present US politics. (Though, in late 20thC, US 'liberals' were still among the strongest free-speech advocates.)
But in the UK & some very-left circles, 'liberal' still has some of those meanings – compared to more radical leftism, for sure – but is often labelled (or slurred) as 'neoliberal'.