Intel's greatest PR success in this mess has been to conflate Meltdown with Spectre. Only Intel is affected by Meltdown because of their design, and it is a more easily exploited bug.
I think that's mainly out of luck. If the exploit had been discovered two years later, the story would likely be different. Apple has been much more ambitious with their ARM processor designs and has shipping iOS and AppleTV products affected by Meltdown.
Shipping or not, it illustrates, that Intel was not unique.
I'm not sure what kind of answer you are expecting. All I am saying is that Intel is not uniquely in the wrong here. There is a whole industry of bad decisions. Whether the decisions were conscious, or only obvious in hindsight I can't say.
"Apple has already released mitigations in iOS 11.2, macOS 10.13.2, and tvOS 11.2 to help defend against Meltdown. To help defend against Spectre, Apple has released mitigations in iOS 11.2.2, the macOS High Sierra 10.13.2 Supplemental Update, and Safari 11.0.2 for macOS Sierra and OS X El Capitan. Apple Watch is not affected by either Meltdown or Spectre." https://support.apple.com/en-us/HT208394
Meltdown is a Variant of Spectre this isn't how Intel classifies it, this is how Google Project Zero, and heck even Intel's competitor AMD classifies it.
It's also not the scariest variant, it's easily fixed (performance degradation aside), doesn't require a microcode update to be fixed hence is 100% software mitigated, doesn't allow you to cross between guest and host memory address spaces and isn't remotely exploitable.
On the other hand variant 1 and 2 are much scarier because they are the complete opposite of Meltdown.
Potentially minimal is probably more accurate. It's workload dependent. In some cases, such as frequent interrupts or system calls on older CPUs without the PCID and INVPCIB features to mitigate the cost, it can be be very expensive.