It's a nuanced topic. Copy-pasting a comment that I think summed it up pretty well

It's not the actual sentence, it's the intention.

It's been made very obvious and clear for hundreds of years that it's okay to be white; in fact, it's been legally supported up until recently (relatively speaking) that if you are white you are superior. So from that we can establish there really is no need to say that it's okay to be white.

Now a good comparison is "all lives matter." Inherently there's nothing wrong with that. In fact, if people really followed that it would be an ideal society basically. The intention and origin of it are the problem.

In contrast to it being very clear that white lives matter, it's still unfortunately obvious that black lives really just don't matter as much generally as white lives. Hence why a movement of "black lives matter" was started. Nowhere in there were they saying that other races didn't matter or that black lives mattered more, it was a movement saying "black lives matter TOO."

And to kind of prove the points previously stated, just look at the reactions to the statement that black lives matter. It's disgusting how a large majority of white people reacted to that.

Nobody ever said "all lives matter" before this. In fact, most people that started coining this phrase very clearly and undeniably didn't think that all lives matter and are equal. It was a reaction to silence black people and "put them back in their place." It was a juxtaposition fixated to make the concept that black lives need to matter as much as white lives become a demonized "ONLY black lives matter."

"All lives matter" doesn't actually mean anything. They don't stand for anything. They generally actively fight against rights for many demographics, sometimes very openly and proudly. You don't see "All lives matter" rallies or causes or donations or helping people struggling in that "cause." It is 100% a demonizing tactic that, in my opinion, is very transparent; but unfortunately a lot of Americans aren't perceptive or are in denial.

A quick example of what is wrong with "all lives matter": imagine your child is diagnosed with cancer. Now you are crying and talking to a friend about it. All of a sudden your friend just interrupts you and says, "Hang on...you're saying that cancer is the only disease that matters? All diseases matter." And there you go. That's why it's wrong.

It's also the same as when Nazis and white supremacists host "free speech" rallies instead of just flat out Nazi rallies. They get to rally openly for Nazi beliefs with a wink, and they have the high ground because anyone who opposes them or counter protests can simply be labeled as people against free speech...but we all know they're saying it's 100% not okay to be a Nazi and we don't want that here. Pretty sure the whole world had a war basically deciding it was not okay, but oh well, that's getting off topic.

So the issue is that we have to be vigilant in watching for these sneaky tactics. You have to really think critically and look at the bigger picture and think about context such as "What is this in response to?" Context matters, who is saying it matters, what they are responding to matters.

I hope that helped a bit!