>then surely it should be at worst unsightly?
What me and other people are trying to get across to you, is that you only feel this way because you support the cause.
The practice of filling every place and institution with your partisan beliefs is a sign of disrespect, essentially a power move. "You're here to read up on an OS, but joke on you, you actually can't escape the all-pervasive hand of my religion. Here's some propaganda diet before you read anything".
To know what that feels, imagine if every time a mainland Chinese scientist published an academic paper they were forced to write at the end "Long Live The CCP" with big bold letters. Or imagine if every time a Muslim scientist published a paper they must write "In The Name Of Allah, God Of All Creation" in the beginning. Etc... Can you see why this is ridiculous to a non-communist or a non-Muslim ?
Why is this ridiculous belief-signalling an expression of power ? 2 reasons :
1- Like I said above, it asserts existence in a space where its competitors don't. No Christian, Jew or Hindu declares their religion in the academic papers they author, it feels fair that Muslims also shouldn't, it's like an unspoken agreement on keeping Academia free of an irrelevant controversial subject that gets people riled up and generates more heat than light. When Muslims (in the hypothetical world) violate this, it's a unilateral violation of the agreement that signals power and superiority. "Rules Don't Apply To Us". It's a fighting stance.
In the concrete case we're discussing here, only progressive tech companies signal their beliefs in this vulgar way, no conservative tech firm have ever put "Blue Lives Matter" or "Make America Great Again" on their technical docs, although there are tens of millions of people who believe just as sincerly as you that those causes represent worthy and moral goals. The reason sane well-adjusted people refrain from expressing politics and religion in workplaces is because of common sense social protocols and unspoken consensus, when you break those, you're deliberately asserting power and inviting challenge.
2- It's probably forced. Just like the vast majority of Chinese scientists or Muslim scientists would probably do the above hypothetical signalling out of fear (of being labelled a traitor and a heretic, respectively), the vast majority of people in progressive-dominated social bubbles probably virtue-signal out of fear, rather than any geniune conviction. It's morally disgusting to force people to express beliefs they don't actually hold, or hold in lesser intensity than being forced to express. It's tyranny 101, straight from 1984.