I believe he is the one who has most encouraged the tendencies which led to the Perl 6 debacle. His strong charisma has made it acceptable to have the following attitudes in the Perl 6 effort:
- Actual use by mortal programmers is boring; satisfying your desire to be brilliant and clever is what matters
- Complexity and obscurity are fun. Perl is good or popular because the language is complex, therefore the next version of Perl should be even more complex.
Perl 6 really has nothing to do with Perl 5. It's more like those movies that say "a movie by the producers of $THING_THAT_WAS_AWESOME" which neglect to mention the script and the director are different.
This is what Conway is claimed to be influencing:
>>- Actual use by mortal programmers is boring; satisfying your desire to be brilliant and clever is what matters [etc]
Go check who wrote "Perl Best Practices". Better yet, read the book.
(And please don't try arguing "REAL influence", or something...)