There is no pro-capitalist Left. That's a polite fiction in the US that no one can afford any longer as the ecosystem is actually collapsing around us."
In the real world, "capitalist" can mean "supporter of capitalism".
From Merriam Webster:
a person who has capital especially invested in business
a person who favors capitalism
Insisting that other people use your restricted definition of "capitalist" makes you look like an idiot at best, and a post-truther at worst. And you're being controlling either way. I'll let you determine if those are good or bad qualities.
And I get it -- I used to do the same. But ultimately I decided that I didn't want to be an idiot, a post-truther, or controlling, so I stopped policing other people's language. They don't need to use words the exact same way I do.
Capitalist and liberal are words with centuries of literature using them to mean what they mean. Then again, it's probably for the best that nobody mistakenly believes you've taken even the most basic steps to educate yourself.