That's probably mostly because -- for a long time -- Lupin the Third
was a difficult series to see, outside of Japan .. due to the fact that Lupin is the purported 'grandson' of the french literary character, Arsene Lupin -- whose stories were not yet in the 'public domain' when Monkey Punch began his manga in the late 1960s.
The estate of Maurice LeBlanc (the author of the original Arsene Lupin
novels) posed a legal challenge to anime importers throughout the 1980s and into the 90s. That's why -- when Streamline Pictures created their original 1980s dubs of The Castle of Cagliostro
, Albatross: Wings of Death
and Aloha, Lupin
-- they went out of their way not to have him referred to as "Lupin"
by the other characters .. who, instead, mostly called him "The Wolf."
Early translation efforts of other movies referred to him as "Rupan"
(a literal romanization of the japanese pronunciation of the characters' name) to get around the lawyers.
Eventually, I believe, 'public domain' finally won the day .. but it still took many
years to see those first couple of TV series get a complete english-language release!
To turn back toward Ghibli (or, at least, toward Miyazaki) .. it's amazing how the Lupin the Third
episodes & movie he'd directed stand so far above the rest of the series, in both storytelling & animation/design quality. Which is no 'knock' on the rest of the series; there are certainly other good episodes & movies .. but Miyazaki's are simply on another level.
There's even a good bit of 'foreshadowing' of his later works, in them; the massive Albatross plane evokes some of the hulking aircraft seen in Nausicaä
or Castle in the Sky
.. while the flying robot featured in Aloha, Lupin
-- ostensibly inspired by the bank-robbing robots in the Fleischer Superman cartoon The Mechanical Monsters
-- can itself be viewed as a direct ancestor of Castle in the Sky's
'robot guardians' of Laputa.
This is also true of the charming 1984 TV series Sherlock Hound
-- called Meitantei Holmes
(literally "Great Detective Holmes") in Japan. This TV series was exactly what its english title implies: the adventures of Sherlock Holmes; but all the characters are cartoon dogs.
Miyazaki directed six of that series' 26-episode run .. and those episodes stand apart, every bit as much as his Lupin
Here, again, can be seen 'foreshadowed' traces of more improbable aircraft and character archetypes which later appear in Ghibli films .. including one episode (The White Cliffs of Dover
) which transforms Holmes' otherwise demure housekeeper -- Mrs. Hudson -- into a supremely confident and 'take-control' heroine, in the Nausicaä