I would agree that Log Horizon didn't need more mortal danger to be interesting. My problem with it was just that it wasn't that interesting. It had some neat ideas, but it spread them too thinly and didn't develop them in the most interesting ways it could. Explanations were quite belaboured, in particular when we get a view of how combat and tactics work in the game's systems early on, but then have a whole arc about the newbie squad learning all that stuff we already know. It would have benefited from being more compressed, I think. My takeaway from the first season was like eating junk food that was tasty enough that I'd finish the bag I'd started, but too bland to entice me to pick up another next time I'm in the shop.

Not to mention that on specific plot/character issues,
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I was put off by the focus on the newbie miko's crush on Shiroe - which would have been just tedious if it were a one-sided hero-worship thing, but actively skeeved me once Akatsuki was shown viewing her as a credible romantic rival - and before that, I felt let down that Lenessia didn't grow into an "NPC princess becomes genuine adventurer" role, but instead acted as a PR figurehead. I just want my lazy, pampered noblewomen learning how to swing a sword and stand up for themselves for real, okay?