That’s an awful elitist attitude you’ve got there, or at least that’s how you’re coming across.
The reason people don’t like the death penalty in PoE is that losing progress sucks. It doesn’t matter how good at the game you are. Losing hours of grind sucks. Sorry, it’s the truth. (See, I can do that too…and we’re both wrong to claim things as fact when these are our opinions, nothing more.)
In PoE, once you break into the 90s, a death really starts to chafe because of the amount of grind time you lose out on. I suspect this is a reason a lot of build guides I look at tend to finish off in the low 90s and consider passive points beyond that to be a bonus. There are people in PoE who like that, and that’s fine.
LE is not PoE, unless I’ve missed a blog post where the devs indicated their desire to build a PoE-like game in terms of difficulty that excessively punishes the player for a single mistake at high levels. (It is also only my opinion, but making a single mistake doesn’t make someone a bad player, either. If someone wants to focus on deathless play, HC exists.)
Also, “casual” tends to mean someone without tons and tons of playtime - not someone who has a hard time with game mechanics. Most people who play games are casuals in the sense that they have responsibilities and can’t sit around playing games all day.