By the time Haskell was first released, OOP was either already available in popular languages (Smalltalk, Object Pascal) or being introduced into existing languages (Objective C, C++, Lisp).
In hindsight it would appear there was no reason not to see that OOP was gaining in popularity, that the term "class" was already in use, and that overloading it would be confusing.
That said, in the end, all my original post was lamenting is that it's a shame that Haskell terminology went the way it did... it's just yet another aspect of the language that creates confusion among newcomers, and it already has enough of that already! :)
The haskell committee were concerned with conveying knowledge amongst functional programming researchers. The use of class in similar but unrelated fields doesn't mean everyone need use it.
Or you can think I'm just flying the mountain with ice cream windows if you like.
Lisp got away with an entirely different meaning for “car” for a pretty long time!
The whole world of GUI programming was based on OO.
The Xerox Star was introduced in 1981 https://en.wikipedia.org/wiki/Xerox_Star
Apple's Lisa was introduced in 1983. https://en.wikipedia.org/wiki/Apple_Lisa
With it, Lisa Toolkit and Clascal (Pascal with Classes) http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/app...
The Mac in 1984 https://en.wikipedia.org/wiki/Macintosh_128K
MacApp in 1985 https://en.wikipedia.org/wiki/MacApp
The Tektronix 4404 running Smalltalk, also 1984 http://www.wirfs-brock.com/allen/files/tek/4404-Flyer.pdf
The Amiga and Atari ST in 1985.
Windows was at 2.0 in 1987.
Heck, the NeXT cube had been introduced by fall of '88.