Yes, DMD uses ld on linux. It's OK because there is no other linker. And it's system's default. Everybody(almost) have GCC.
But on windows.. MSVS is external IDE and toolset. Some people yes they uses MinGW. Why ? MSVS has some disadvantages for me for example it's poor C++11 support. So it's useless in my work. So for compile 64 app with DMD one must download dmd(~20 MB) and install MSVS(~2 GB). I think dmd should work out of the box isn't it ? And what about other compilers ? Latest LDC for example uses 064 frontend. It's outdated for me because of bugs. I cannot ever compile my app now with it. With GDC it's alto difficult to get luck.
