If your memes are too spicy you'll get HR try to turn a critique of something being bad or underfunded into a personal attack on people that put a lot of effort into something no matter how broken it is. They'll pull strings and you'll have to speak with your manager about it and even if they agree it wasn't a personal attack, they'll push you into not doing it again and just lay low under their radar. It's not the usual though, so maybe it only happens if someone feels attacked and complains to HR about it?

Memegen is something that HR wants gone, but knows it cannot afford to take away as they already made Google a worse place to work at during the past 10 years. They already sort of hijacked it and took control of it.

I've worked 12 years at Google. When I was tech lead, I periodically checked Memegen and searched for my project name. I found it useful to get this feedback. Sometimes I converted the meme into a proper bug report; sometimes I responded to the meme with an explanation.

Not everyone will use Memegen in the same way. But quite often a high voted meme can be treated like a high voted bug report. It provides signal to the team.

Note that I worked on internal tooling. External facing teams have lots of other feedback channels, and they know that Googler's feedback is biased. So how the team responds to the feedback can be vary a lot.

I haven't worked there in several years, but assuming memegen hasn't wildly changed: Management likes having a pulse on employees, and they tolerate memegen since it's mostly fun, it builds shared culture in a massive company, lets workers (mostly) harmlessly blow off steam, and it would be massively unpopular to shut it down. Management does not like that memegen is often a nexus of cynicism and employee activism. Also in my experience, most employees were nearly completely agnostic or ignorant about whatever trend was on memegen, so it wasn't necessarily representative.

Yes. This is considered pretty tame and the lines you can’t cross mostly involve other people or groups of people (reasonable).

I suspect that someone at Google has read economist Albert O. Hirschman's treatise on Exit, Voice, and Loyalty [1]. The central idea is that when people are unhappy with a relationship between themselves and, say, a firm, they have basically two options: (1) Exit, that is, leave the relationship; and (2) Voice, signal their unhappiness. Hirschman argues that encouraging one option reduces the inclination to exercise the other option. Further, he argues that when people Exit, the firm has little opportunity to understand what motivated the people to leave, so it is advantageous to shift people toward the Voice option, which conveys that precious information readily. So, by allowing Memegen to exist and be used, Google management gives employees a way to exercise Voice instead of Exit, and management learns more about what people are upset about on the margins of the employee base, giving management an opportunity to respond (which they are free to ignore if they want).

https://en.wikipedia.org/wiki/Exit,_Voice,_and_Loyalty

When I worked there a few years ago, if you made a meme that made anybody unhappy, there was a team in corporate that woudl threaten your job to make you delete it.

Yeah, look at how Google treated employees that protested against Palestinian genocide. Immediately fired and violently removed.