If "Black Lives Matter" or "All Lives Matter" is something that angers and offends you regardless of context, or is something you feel the need to argue against because if how some people have used words in that order...
Might be a good idea to stay off the internet a while. Maybe do some self care. Get laid, get paid, or find the right kinda drugs for a bit. Try building a ship in a bottle.
BLM started as an organisation, and some of what they advocated was Marxism.
However, most people who sympathize with the phrase today are more blm than BLM, and don't sign on to the entirety of the original intent... Instead seeing it as shorthand for things like opposition to police brutality and supportive of institutional accountability.
This is the problem with simplistic slogans.
All lives matter, or should.
Which means all black lives matter, or should.
Some people may use ALM to be dismissive, and some people may use BLM to be exclusive, but...
Both statements are or should be true.
Someone says "BLM", and someone responds with "ALM"...
Chances are the BLM person will respond by pointing out ALM is insensitive or BLM is addressing relatively unique concerns.
Seems to me a better strategy is to say "You're right. All lives matter, and more than just black lives are impacted by police brutality (even if it's disproportionate). This is why you should support an end to qualified immunity and no knock raids."
Instead, many activists shoot their cause in the foot by proceeding to make an enemy rather than an ally.
I don't say "ALM", because it's often unproductive to what I try to advocate.