Either the author is not explicit enough in the article, or he makes a critical, wrongful assumption. Either way it's dangerously misleading.
Sadly, I'd lean towards the second one because of text like this:
> A major difference between software written for CPUs and VHDL is: VHDL is concurrent by default.
VHDL is a description language, not a programming language.
When writing VHDL you are not, at any point, writing software, you are laying out a map of the hardware. This map describes physicalities, and (barring relativistic considerations) physics happens everywhere at once. It is not parallel computing, it is physics.
Sadly, I'd lean towards the second one because of text like this:
> A major difference between software written for CPUs and VHDL is: VHDL is concurrent by default.
VHDL is a description language, not a programming language.
When writing VHDL you are not, at any point, writing software, you are laying out a map of the hardware. This map describes physicalities, and (barring relativistic considerations) physics happens everywhere at once. It is not parallel computing, it is physics.