Why? Firstly because they are made by coders, not electronic engineers. They perfectly understand the code but not circuits, electronic components and physics. We are both: programmers and educated electronic engineers with more than 18 years of experiences.
And also... basic code cannot behave like electricity in real analog circuits.
That is a reason why we developed our own virtual circuit technology. We are emulating whole analog circuits, electronic components and modules of synthesizer + their behavior in various situations, noises, feedbacks, interfering signals etc.
Home Page -

https://eplex7.com/klerhaim-n1-analog-vst-plugin-synthesizer/