i guess the point is that z is a common complex variable (one that has an imaginary component) like 3+2*i, kind of like how x is a common real variable, and that oo is a cute way that they write infinity in ascii like it's the sideways 8 symbol except written like oo. that said, i think it's dumb and i also think that way to write infinity is dumb.

I agree. While it might look obvious in hindsight, I think programmers should stick to names that are less confusing. Something like CmplxInf would have made me guess "oh, it's probably complex infinity".

Given the fact that infinity is expressed as sympy.oo in sympy makes the use of sympy.zoo somewhat consistent/unsuprising.

Maybe the OP of the tweet was/is not aware of this use. I wonder if his next tweet will be about sympy using oo for infinity.

Person claims to be a 'Marketing PhD candidate', I'm not sure they have grounds to be complaining about any kind of net utility.

that’s inappropriate and reminds me of the stereotype that “marketing is all about profit”. There are tons of marketing papers talking about ethical things useful to consumers.