Wasn't it based on the GB link cable?

No, they both used the same physical form factor, but it seems to have just been a model from a OEM used by both nintendo and apple around that time, rather than one spec deliberately copying the connector from the other.

I’ve seen that claim but AFAICT it comes from a single source, which was a presentation by someone involved in the FireWire connector design. So at this point it’s more of an urban legend, until we have some solid confirmation.

It does not really matter though, they are very similar in construction, and are very sturdy, and I really like them both :)

I've seen the same claim made. Apparently it was the sturdiness that led to it being copied. Good enough for kids beating on it and stepping on the ends, more than good enough for professional applications.

The 6-pin connector was nice. But laptops and camcorders generally had the 4-pin connector (sans power)...not so nice.

Indeed. The small one was very flimsy and annoying to use.