Am Fr., 4. Jan. 2019 um 16:55 Uhr schrieb V.Liepelt <V.Liepelt@kent.ac.uk>:

Hi Sven,

[…] section 11.1 [of the Haskell 2010 Report] explicitly states that all derived operations for Eq and Ord are strict in both arguments.

Good idea to look at the Report. Unfortunately it doesn’t give any reasoning as to why this choice was made.

As I said: Consistency. (Well, I didn't write the report, but this seems to be the most obvious reason.)