Another instance of Larian undermining the roleplaying that they've otherwise worked so hard to enable. Yeah, it's a brutal choice to literally snuff out a life, but on a first playthrough you're not going to get the heightened effect of having to kill someone you know because you don't find that part out until after the choice is already made, sometimes long after. Thus, you won't have to weigh your options and make that choice in the moment. Also, instead of horror when you're confronted with the results of your choice, your first reaction is more apt to be frustration that you've unknowingly eliminated what may be an indispensable character, depending on your build. I don't think "frustration" is the response the developers were trying to elicit.
On any subsequent playthroughs, the impact is sucked out of the choice because, if you're smart, you'll make sure to purchase everything you need beforehand, thus rendering the character unnecessary and his loss trivial, especially since he's not a character with whom you develop any kind of emotional bond.
Also, to clarify: Almira, if she's on your ship, sells Aero/Hydro/Pyro books, and Gareth sells Geo books, but no other trader--that I've been able to find, at least--sells Poly books.
Last edited by JosieJ; 10/11/17 04:59 PM. Reason: Clarification
