I understand that there will always be outliers. The stamped steel stem in the picture is about the least expensive way to hold a handlebar, typical in a department store bike. If the bars are similar, they'll usually bend when you hit a big bump - one tongue-in-cheek bike magazine review of a Huffy proclaimed that the bars were reversible, i.e. you bend it down when you land a few times, flip the bars back up, then do a few jumps to bend them down again.

There are good quality steel stems (again, I've used them, and I still own a bunch). I don't own any good steel bars, nor do I own any good steel posts.

Whenever I use a breaker bar (and they're inevitably steel), I use gloves/rag/something or steel myself for some tingling hands. Break loose (distinctive crack as it starts to turn) an axle bolt or crankshaft bolt or even a pedal and I feel incredibly sharp pain in my hand. Maybe it's just me.

Also, although my general points in my first response may not be an end-all, the idea was that aluminum is not necessarily harsh, nor is steel necessarily soft. In general you can make a material do what you want; costs and generally accepted business practices limit material use. So, although there are aluminum hammers, they're not the normal hammer in a hardware store (we have none here). There may be aluminum springs, but steel ones are cheaper and more plentiful. Etc etc.

I only describe what I've experienced. I wanted to love but ended up hating the soft aluminum and carbon Vitus frames. I wanted to love but hated my very pro but very flexy Tange Prestige frame. I wanted to love but hated my very pro Cannondale 3.0 Road frame (too flexy). I loved but then hated my very-un-pro Cannondale 3.0 Crit frame (I thought it was great until I hopped on it in a race after I wrecked my new primary bike, a Cannondale 2.8, and my hands started going numb almost immediately, and yes, I had slightly different steel stems, virtually identical tubulars, and slightly different alum forks on the bikes).