PS/2 ports may be preferred in a corporate setting for security concerns since they allow USB ports to be completely deactivated, prohibiting the attachment of any USB portable drives or malicious USB devices. [9]
The PS/2 interface does not impose any limitations on key rollover.
Due to driver difficulties or a lack of compatibility, some USB keyboards may be unable to access the BIOS on specific motherboards. BIOS is nearly universally compatible with the PS/2 interface.
When KVM switching with non-Windows computers, PS/2 ports generate less issues.
USB:
USBs often have reduced latency.
On a keyboard, they have at most a 6-key rollover, however there are workarounds depending on the operating system and BIOS.
USB is far superior to PS/2 for hotplugging (you must turn off a PS/2 PC if there is no PS/2 device in the port during PC activation, and it is still not suggested to "hot-swap" a device in PS/2).
PS/2s were not meant to be repeatedly disconnected, hence they are not particularly durable for that purpose.
TL;DR: The USB is superior in most use scenarios, which explains its widespread acceptance.
