The original AMD64 extension and associated ABI included SSE2, so vectorization was available on 64bit x86 systems from day one. I think that's at least 17 years if not 20. GCC will use it by default at O2 starting with their next release in about a month. Intel has contributed for a long time but I dont know that this stupidity could be pinned on them. It wouldn't surprise me though.
thats a typo .. are you showing a case of AVX instructions not generated by GCC? where are the details here? Is SSE2 from twenty years ago?
https://en.wikipedia.org/wiki/SSE2