I'm inclined to believe that this is actually the case and not that AMD wrote more secure software. All software has security vulnerabilities, the more eyes on the software the more of them are found.
This isn't "Software" It's hardware (well both but lets not get too pedantic) and everyone was throwing cache and speculative exploits by the shovelful at both AMD and Intel. AMDs are indeed at the very least, "Less insecure."
Way more shit stuck to Intel for one reason. The speed advantage Intel had been lording over AMD (Besides compiler shenanigans) was all the corners they were cutting with there speculative execution, et al.
Amazing timing that; AMD closing those benchmark gaps and the mass meltdown mitigations in Intel products... all in the same decade Intel was court ordered to fix their unfair C compiler. Intel's domination is simply over...
