"It was never designed or meant to be used as a combat rifle."
Wrong, Ruger sought combat orders. The fact that other nations in the 1970's didn't choose it was the fact that many were still using the FAL, others were trying the AR, and none of them wanted a wooden stock. However, for the first several decades, the Ruger was the rifle of choice for virtually all police forces in America. The AR has largely replaced it but that was due in no way to failings of the Ruger. The AR came as pollice became more militaristic. Even then, that is not the AR's fault, but the Minis in service had been in service for several decades - it is not uncommon to surplus arms in service for 30 years. Even so, the AR that replaced the Mini is NOT the AR that competed against the Mini. Nobody replaced the Mini 14 with an AR design of the same era.
You can't really compare, as there are no Blackthornes making Mini-designs. But the Mini-14 is a solid, well-built rifle regardless of AR aficionados' preferences. Yet, they compare the current AR to the Mini, a design which is 40 years old. Admittedly, Ruger didn't update the Mini 14 and it's current rifles are no longer really geared towards the military markets any more, but when apples and apples, Mini 14 of 1970's to AR of 1970's, and the two rifles are far more comparable. The basic design of the Mini is in no way at fault here.
The m14 is obsolete only as a general issue infantry rifle and even then solely because it was a full-power rifle that arrived on the scene at the dawning of the assault rifle. As a DMR, it still shines. Yet, the M16 is also obsolete as you could do nothing at all with the platform other than shoot it - scoping was a real joke. No major combat force uses the M16 of the same design era as the Mini these days. The original AR upper - the one in use when the Mini came out - could not mount optics worth a crap and the iron sights had limited adjustability. The current AR is not a 50 year adopted rifle as many now claim, as the rifle they carry now bears little affinity with the originals beyond trigger group, bolt, and receiver. You can customize an m16 no better than a Mini-14. You have to replace major parts of the m16 to customize it (IE, completely replace the upper and butt stock in order to achieve nirvana). That is alot of changing. I could do the same level of changing with a Mini and end up with the same level of customization and attachment of accessories. It took significant redesign of major components to get the AR to the state by which all judge it today. Give me the redesign time and effort employed on the AR and I could achieve equal results with the Mini. Heck, apply the same EBR updates to the M14 to the Mini and you could get virtually the same.