I think the person the questioner was talking to was a tad out of touch. And we see that regularly on Slashdot with people absolutely convinced that $TECHNOLOGY is never used because they don't see it used in their circle of technology acquaintances.
LAMP is generally used for a lot of new projects that end up phenomenally successful but start as essentially hacks where someone wanted something and didn't know much about coding, but knew enough PHP to put something together that did what they needed.
Objective C on iOS and Java on Android are, obviously, the two major mobile platforms. And C++ is used on Windows because it's what was, until recently, the only standard Windows platform and a large number of Windows developers are still wary of .NET.
Even outside of the golden seven, we have languages like C that still serve a critical purpose in some domains such as kernel level systems software. And what remains is mostly a set of platforms that aren't "legacy", just not as popular. Python, Perl, node.js, Coldfusion (another platform I'd wish would die already, even more than PHP), Ruby, and others.
Legacy? I guess nobody's doing new COBOL development to the best of my knowledge, or new Fortran. Some would dearly like Adobe Flash to be legacy, but until a viable cross-platform DRM scheme gets added to HTML5, I don't see it going away.
But .NET? Claiming it's legacy shows astonishing ignorance.