Wait, you have to use
both Spacebar
and LMB?

I've never seen any game ever that required multiple buttons at the same time. For instance, I'm sure nobody would ever require W, A, S, and D controls while also having players use LMB to shoot at a target. I've also never seen one using a controller's left stick while pressing a button on the controller's right side. Two things at the same time is definitely abnormal and "atrocious coding". Yep, yep. For sure.
At least I can agree with your point about scrollback. It would be nice to be able to back up in some places. Hardly a deal breaker for me or anything, but I could see it as a nice-to-have. However, that has
nothing to do with coding issues. It's a design choice. Maybe you don't like the design choice, but it has absolutely nothing to do with the dev failing to code something well.