OK, so here's a thread about astronomy, constellations, magnitudes, parsecs, Pop I and II stars, and all these crazy units and lingo we use as astronomers. Because I am *constantly* reading threads bitching about these things, and I'm here to push back a bit.
First, to be honest, MOST of the time I encounter that view, its from physicists buffaloing into the astronomical literature and deciding to explain to astronomers how we should be doing science. "Why can't you use proper units? What is this magnitude nonsense and parsec stuff?"
And then I go and look at physics papers and see energies expressed in MeV and crossections in zeptobarns and setting c=1 and all that nonsense and I'm like "Riiight."
So yeah, physicists, take some time to learn a field before deciding things are being done wrong. Taking a log and multiplying by -2.5 isn't all that hard. You can do it. I know you can.
But I *do* have sympathy for students. It can be confusing, particularly when all you've been exposed to in your classes is SI units. When professors give you overly idealized problems with homogenized units, it can be confusing to suddenly see real data and contextual units.
And then: what is this Pop I vs Pop II stuff? Why are stars classified in this OBAFGKM sequence? What *is* a late type galaxy vs an early type, and why *do* we still talk about galaxy morphology in terms of the Hubble Sequence?
So yeah, learning magnitudes and working out terminology can be a bit daunting at first. I get that. But I love the lingo of astronomy. Not because I am an elitist who wants to throw up barriers to understanding, but because that lingo carries the historical context of our field.
I appreciate knowing that the flux units I use are rooted to the ancient astronomers who first were sorting stars by relative brightness. 
That this parsec unit we use so ubiquitously is based on the most fundamental scale of distance in astronomy: the Earth-Sun distance.
I appreciate knowing that when I talk about Population I and Population II stars, I am using the language of Water Baade, who used the Mount Wilson 100" telescope during blackout conditions in World War II to study the stellar populations in the Andromeda Galaxy.
And when we talk about coordinates using these crazy sexigesimal units? Objects rise, objects set-- our sense of time and the motions of objects in the sky are linked by the rotation of the Earth and the Earth's motion around the Sun. The sky is a clock, people!
Constellations: I love looking up at the sky and seeing Orion battling Taurus, or Sagittarius drawing his bow on Scorpio. To simultaneously know that Orion houses our best view of the process of star birth?
That in Taurus I see the linchpins of our astronomical distance scale: the Hyades and Pleiades cluster?
That when we look at Sagittarius, we look at the center of our galaxy?
All that is spectacular. The sky is a cultural story and it cradles the scientific questions we are trying to answer. My great failing as a scientist is NOT knowing the full multi-cultural story of the sky; ignoring its significance would be even worse.
When I teach astronomy to our majors and our grads, I try to teach all of this stuff. The geocentric vs heliocentric universe? The controversy about the distance to the spiral nebulae? Unravelling the zoo of AGN taxonomy?
Yes, it takes a while to learn, but its really important for understanding how we got to where we are. It's how we become better scientists, by acknowledging our scientific past.
So yeah, I get that there is a lot of confusing nomenclature. But astronomy is often called the oldest science, and as an astronomer I feel a certain obligation to respect and acknowledge that history, and to root my science within the context of my scientific predecessors.
"Speaking astronomy" -- in terms of language and units and historical context -- is part of that respect.
My mother always said I needed to understand the history of my field. To pay attention to what has come before. She wasn't an astronomer, but she was spot on absolutely right.
So, yeah. If you take astronomy from me, you're gonna learn some scientific history as well. And you're gonna learn magnitudes. And spectral types. And constants in non-SI units. Because that's how we astronomers roll. That's how we've always rolled....
