Because control should be where caps lock is on most keyboards.
It is the one key re-map I cannot live without.
(Anyone who used a Sun keyboard for a considerable period time is familiar with this layout. I do not know if any other systems predated Sun in this regard.)
Sun (founded 1982) was certainly not the first. The Apple II (1977) put CTRL to the left of A, and every other II followed suit. I'm sure they weren't the first, either. The original IBM PC's Model F keyboard (1981) put control to the left of A, too.
The Macintosh didn't originally have a CTRL key, so Caps Lock went there. The first Mac to have CTRL seems to be the Macintosh II and SE, where you were offered the choice of the Apple Keyboard (control left of A) or Apple Extended Keyboard (caps lock left of A). Thus began decades of confusion.
Interestingly, the NeXT keyboard (1988) had no caps lock.
> (Anyone who used a Sun keyboard for a considerable period time is familiar with this layout. I do not know if any other systems predated Sun in this regard.)
I believe the ASR33 may be the originator of Ctrl to the left of A:
Other influential terminals such as the DEC VT series, and the ADM-3A also placed Ctrl along the home row (although on many of the DEC keyboards, there were two keys in the modern Caps Lock position - Ctrl to the left, and Caps Lock on the right).
Many early home computers had Ctrl in this position, including the Apple II and the original IBM PC.
The very first Sun workstation used a keyboard with the same layout as the DEC VT100, it then evolved into the more well known Sun layout, which later inspired the Happy Hacking Keyboard,
Because ctrl is important for terminal users, but Mac keyboards have it only in a very awkward almost unreachable place - so remapping caps lock to ctrl is a very common fix (which is supported natively in the settings app, too).
It is the one key re-map I cannot live without.
(Anyone who used a Sun keyboard for a considerable period time is familiar with this layout. I do not know if any other systems predated Sun in this regard.)