Focusing by itself is bad. If you have a notice pop up over anything, you will loose focus; the popup will steal it.
That's actually not true for ALL popups within Steam client. About half of them are done right, e.g. those on individual games in Store section, central part, but not those in Store section, "Specials" part on the right. I opened a separate issue report (https://github.com/ValveSoftware/steam-for-linux/issues/14) for that.
This bug makes it impossible for me to click most dropdown menus. They close immediately while the main window gains focus again. At rare random occasions it works though.
Xmonad on Arch Linux, no desktop environment.
I see the bug. We have 2 other focus related issues we're working on right now, this will get added to the list. Thanks.
The unfocusing bug is fixed and will be in the next update (after New Years). Also the focus stealing by notification windows is fixed too.
This is indeed fixed in today's update. Thanks!
I have KDE set up to make unfocused windows somewhat transparent, and whenever I click inside Steam window (anywhere, even on an empty gray space on the side), I see the whole window get transparent for a split second. This indicates the window loses and regains focus during a mouse click event.