Think harder. Logically, both are counterpoints to someone saying that black lives matter, disingenuously attempting to muddy the waters by implying that we're hearing "only black lives matter" when literally no one, anywhere, was saying that. It's the racist's version of snowflakery, finding a nonexistent reason to be offended ("they think only black people matter??") and screaming about it. Both phrases are trash in the same way that the textualist "we just care about all people" fake-innocent defenses of them are trash, and any actual "logic" will generally lead right back to that.