Well, that shows what little I know about the Hugo and of fandom.
I don't disagree that others have that opinion about Star Wars. That's besides the point. You claim is that Babylon 5 is not part of science fiction. You think that the allusion to what other people think about Star Wars is relevant to your claim. But as you must well know, that question of "is Star Wars really science fiction" is old and well-worn (eg. http://pop-verse.com/2014/12/10/is-star-wars-science-fiction... ).
It is therefore a poor tool to use to answer the question of 'is Babylon 5 science fiction?'. My objection was to this use, not that others believe it to be fantasy.
This concept of "speculative fiction" as an encompassing term is a perfectly reasonable one to have. However, it does not address the question 'is Babylon 5 science fiction?'.
You can place Hitchhiker's Guide into "Comic Science Fiction", but note that "Science Fiction" is in the name. Granted, astronomers say that a dwarf planet isn't a planet, but a dwarf star is a star, so it's not always possible to infer an is-a relationship in a name, but so far it looks like Hitchhiker's Guide is part of science fiction.
You give what you say is the "classical definition" of 'a work of fiction that uses science as a story telling device to explore ideas'.
As you must surely know, there is no such classical definition, and "its exact definition remains a contested question among both scholars and devotees." (Quoting https://en.wikipedia.org/wiki/History_of_science_fiction and reflective of my understanding.) Furthermore, there's an entire section in Wikipedia on just that topic, at https://en.wikipedia.org/wiki/Definitions_of_science_fiction , many of which are not limited to your 'science as a story' definition.
I can assume your definition for argument's sake, but you still haven't answered the question of which TV series you think is actually science fiction under your definition, nor have you given any books.
This unwillingness to state examples is why I'm getting gatekeeper vibes from you. (A gatekeeper who is used to shutting people down for using the wrong terms is often one who does not want to stick a neck out for worry that it will in turn be cut down.)
Do note that the "science fantasy" link you give says the term "has never been clearly defined". The Heinlein example of 'Magic, Inc.' has many of the tropes of outright fantasy. I would consider "Glory Road" a better example for this category, with mixed fantasy and science elements. Indeed, if you look in the talk you'll see a raging discussion on just that point. In any case, 'Tunnel in the Sky' has no fantasy elements, so cannot fit into this category.