Well it is not unlike criticising an artist's paintings. The things you make are a mirror of who you are because you use your life experiences, knowledge, and preferences to make them. By criticizing what you make, they are also criticizing you by proxy.
Now sure it depends on the type of criticism in question. Finding a bug or other practical problems obviously isn't, but talking shit about a way something is arbitrarily set up that the author thought was really neat would absolutely be.
This line of thinking also reminds me of how every time some actor or director or whatever is implicated in some scandal, their work is also tainted forever instead of being taken at face value for what it is. Can we separate the artist from their art? Is it even possible? I doubt it.
You had better believe that when artists get a commission, the patron gets a say in how the work looks. When you are in a band or ensemble with other people, they also get a say in how "your" part of the music sounds. This is the same for code. Code you create with and for other people isn't really your creation in that way: all of it is a collaborative effort.
I don't think that really changes anything, just restricts the effective criticism to that specific part that you did. Though I suppose the more it's intertwined the less it matters. I don't think anyone really cares about that one function in the company codebase that's been rewritten 20 times by different people, and far more about that part of the game they coded themselves at a gamejam.
There's always external influence, but if you're involved you obviously added something and in most cases it can be scrutinized on its own merits.
To rephrase, criticism/review of your code doesn't reflect a value judgment of you as an individual any more than an artist's patron asking for more blue-ish tones reflects a value judgment of the artist. The patron doesn't think that you have any moral faults because they want more blue, they just want more blue. The same goes with criticisms of code.
Code is made to be efficient in a compagny, it's not "personal" or here to make you have feelings. So if you can't discuss efficiency because you'll hurt people it's just bad. If you do art, you create art with respect to your own sensibility emotions so yeah be weary of criticizing someone's art.
Now sure it depends on the type of criticism in question. Finding a bug or other practical problems obviously isn't, but talking shit about a way something is arbitrarily set up that the author thought was really neat would absolutely be.
This line of thinking also reminds me of how every time some actor or director or whatever is implicated in some scandal, their work is also tainted forever instead of being taken at face value for what it is. Can we separate the artist from their art? Is it even possible? I doubt it.