First, no computer programmer is going to "dis" any potentially valuable tool. Assembly has huge disadvantages in the areas of maintainability and portability. In the example I gave, it was a multi-core processor, but even so the best product solution required assembly code.So far the inputs tend to dissing assembly over the usage of several cores for speeding up the process...? So ASM seems to be losing the privilege it's so proud of?
When it comes to cores vs. assembly code, you shouldn't expect that increasing cores will necessarily buy you what you need no matter how many there are. If you are driving a serial process where every step requires the results from previous steps, extra cores will buy you nothing - the oft-stated situation of 9 women working on a pregnancy.
In cases where there is a trade-off, you need to weigh the advantages of portability and maintainability over the advantages of a smaller physical package, less power and heat, cheaper BOM, etc.
Assemblers "privilege", as with any tool, is in its utility and economics. Certainly, there was a day when tripling the execution time meant that you only had a one-room computer system with associated power, floor loading, and air conditioning instead of 3 - or you completed a data run in 1 week instead of 3. You can still have those trade-offs today, but they are far from typical.
More importantly, optimizing compilers and linkers are now really good. Not just any assembly will beet the compilers - only assembly that is very targeted and carefully written.
To give a sense of this, fourty-five years ago on average a line of assembly code was faster to write that a line of RPG, COBOL, or Fortran. That's totally untrue. Assembly coding is no longer that casual. In general, any assembly code written today will have a C/C++ version written beforehand or at the same time - and a timing comparison will be used in making the decision which one should be used. It's usually a big deal.