But I don't understand why the hole must be super-massive to produce jets. AFAIK, any black hole consuming matter from accretion disk may produce jets, just with different speeds. So super-massive holes may create jets up to 0.8 light speed (at least thats what Hubble has caught on camera). And smaller holes would produce slower jets.
Ugh. I think I should start again with this argument because I've kind of botched it from the start.
Okay, we're looking at a visual representation of a black hole here, so the question is not so much "what exists?" as "what can you see?" What is producing light in a visual spectrum, and in the case of a black hole with an accretion disk the question becomes even more complex because the entire accretion disk is emitting varying degrees of radiation, including visible light. So the question is, are the jets significant enough to see? Do they warrant inclusion in what is meant to be a fairly general depiction of a black hole, and in almost all cases the answer is "no".
And yes, it's not just a question of size, it's a question of the volume and energy of matter being ejected in the form of a jet. If the hole is large enough to accelerate matter to something close to the speed of light, then that matter will be highly energized and probably giving off a lot of radiation, potentially making it visible (or at least worth depicting). If huge amounts of matter are falling into a black hole, such as a massive star being torn apart, then the volume of matter being ejected is also going to be significant enough to potentially be visible (or at least worth depicting).
However, to say that depicting a black hole without visible jets is wrong is completely not true, even if it is technically true to say that the same processes which produce visible jets are occurring in all black holes. It is completely dependent on the size of the hole and the amount of matter which is falling into it at any given time.
I stand corrected on evaporation though. I'm not really up to date on that because astrophysics isn't my field, but hey, at worst I'm being one of those amateurs who talks down to people who actually know what they're talking about, and given how often I get talked down to by amateurs in my own field I figure I deserve to be on the other end for once!