The question is simple. I only ever seem to find a soldering-related hot air gun on a machine dubbed a “rework station” and the only reference I can find to using hot air to solder SMD components is on a few YouTube videos. Is a hot air gun on a soldering station really only designed for desoldering and some people tend to, I guess, “misuse” it for freshly soldering parts?
It's not really a misuse to use a hot air hand rework station for soldering parts, but it would be uneconomical to solder whole boards with it in a production setting. Getting consistent, high-yield results when soldering hundreds of SMT parts by reflow requires careful control of the time-temperature profile, which is very difficult to achieve with a hot air gun. It also involves exposing various components to repeated hot-cold cycles as you move the gun around the board, which is punishing treatment for them - most are only rated for 3 or so reflow cycles.
For prototyping purposes, if you don't want to use a proper reflow oven or the cheapie toaster oven equivalent, the best bet is probably to solder all parts with leads using an iron and a drag-soldering or flood-then-wick technique. Use the hot air gun only for the bottom-terminated components, and accept that your yield isn't going to be 100%.
A rework station is different than a "hot air gun" or "heat gun," which are similar but don't have precise temperature controls. A rework or reflow gun/station can be used in any application where heat is required at a precise temperature. You will see some desoldering, resoldering, or just directly soldering a fresh component. Things like solder paste combined with existing solder masks, make it fairly easy to apply paste to an SMD component, apply some hot air (set to the temp solder temp) and the melted solder will wick to the board and SMD contacts. Aside from that, it has many other uses (like heat shrink). It's a tool just like any other, though don't fall for everything looking like a nail kind of approach.