I chose to use that word to preempt nitpicky objections about measuring oxytocin in dog brains (which doesn't actually tell you anything about the subjective experience the dog feels.) 'Qualia' refers specifically to the subjective conscious experience, which is something science is presently ill-equipped to answer questions about. The word 'qualities' does not have the same rhetorical effect.
As an aside, what's the point of complaining about uncommon words? Dictionaries have never been more convenient to use. If you didn't know the word before, then in about 5 seconds you can learn what it means and your personal vocabulary will be enriched.
Precise language is useful for discussing complex ideas precisely.
If HN is to be a place for gratifying intellectual curiousity [1], then dismisisng dismissing accurate terminology as pretentious purely because it is unfamiliar is counter-productive.
“qualia” are the internal experiences of sensory perceptions of the subject, “qualities” are the attributes of the subject. They look a bit similar, and are etymologically connected, but their denotations are about as far apart as is possible for words that are the same part of speech.
Qualia are not limited to sensory perceptions. We have conscious experiences of things internal to our minds too, such as emotions and thoughts and memories and these too have qualia.
Qualia is your subjective experience of your senses - how can we discuss whether we see the color red the same way, or whether we smell a rose the same way? The core concept we would discuss is qualia.
Qualia is not plural qualities so I’m afraid I don’t see the connection, or the downside to using an expanded vocabulary for that matter.