I had no idea what you’re talking about so I had to look it up 🙂
I think you’re making assumptions on what I need many serial ports for and it’s nothing like what you think.
I work for a company that makes measuring instruments that talk serial (RS232, RS422 and UART), we have many variants of our products and I’m tired of plugging and unplugging devices to the same serial ports to test code. Also, I can’t do that remotely when I work from home. So I have many serial ports and all the different devices I need to test my code on regularly are all plugged in and powered at the same time.