If a program other than the foreground program requests elevation, instead of interrupting your work (the foreground task) with a UAC dialog box prompt, UAC signals its request with a flashing taskbar button. Click the taskbar button to see the UAC prompt.
Apparently, the idea is that UAC prompts will not “steal focus” from the user’s task. You should click on the flashing icon.
This is not all Microsoft's fault. Some products are badly programmed, so although their window is the current focus, they don't pass that window's handle for UAC to use. In that case, UAC will not put its dialog in front, but will rather signal its presence thru the taskbar.
And for the last question: Microsoft Engineers are mostly found in Microsoft Way, Redmond, Washington.
You might check if in Local Security Policy (or run gpedit.msc) / Local Policies / Security Options, the value of "User Account Control: Switch to the secure desktop when prompting for elevation" is set to Enabled.