Am I seriously going to be the only guy that questions what this guy has that only gives him access to OpenGL 2.1... but it's perfectly ok with Directx 11?
Intel hardware, probably. They pushed out DX11 drivers for a number of chips but never bothered with GL support, and the chips are now old enough that they no longer receive driver updates (and hence will never get GL support despite being capable).
Alternatively, it may just be old D3D9-era hardware. Microsoft actually put a lot of effort into DX11 emulation aka "WARP" (mostly for debugging and verification purposes) so you can run DX11 code just fine on old hardware; it just won't be particularly fast.
There's also plenty of hardware (also in the "older" bucket... mostly) that had newer GL drivers but they never worked particularly well. Which is precisely why GL|ES wrappers to D3D (e.g. ANGLE) exist and why all that fancy WebGL you run in Chrome or Firefox on Windows is actually driven by Direct3D and not the native OpenGL drivers.
Finally, there are also platforms like OSX which do actually support newer GL but only when the API is initialized in the non-default Core mode. The default Compatibility mode is capped at GL 2. The same hardware on Windows will likely have DX11 support. This confuses a lot of people as none of non-Apple desktop platforms have restrictions on Compatibility mode features. It makes porting a surprising pain for a lot of hobbyists because most OpenGL ends up being an unwitting mix of Core-approved and Core-deprecated API calls, given how awful and spotty the popular GL documentation and tutorials are.