We can spend all day analyzing Lucas quotes from the last 40 years, but we can’t avoid the obvious fact that significant parts of The Phantom Menace are just obviously tonally different than the OT. Specifically, TPM relies heavily on slapstick humor for comedy relief. Whereas, comedy in the OT was derived mostly through character interactions and dialogue, like Han Solo bickering with C3PO or Leia, C3PO bickering with R2, etc.
To be clear, I’m not saying the OT had zero slapstick comedy (examples of OT slapstick include C3PO kicking R2, the Sarlacc burping, Ewok antics in ROTJ, etc.), just that it had way less than the Prequels, to the extent that we can accurately describe OT comedy as mostly defined by character interactions and dialogue. In contrast, TPM had very little dialogue-based comedy (a few one-liners from Qui-Gon or Obi-Wan), but heavily featured slapstick Jar Jar antics, like stepping in Bantha shit, dropping things, getting electrocuted, basically the entire Gungan battle at the end, etc.
Slapstick comedy is generally considered more juvenile, and is often one of the main forms of comedy in children’s movies because children universally understand physical comedy. That’s why Phantom Menace seems more explicitly designed for children than the OT. So regardless of anything Lucas says, the fact is that Phantom Menace objectively relies way more on slapstick comedy than the OT does, making it a lot closer tonally to movies that everyone agrees are made for children (like Disney/Pixar cartoons).
There’s a scene in Watto’s shop where Jar Jar performs slapstick antics in the background (juggling, dropping things, getting kicked by a droid) for a good portion of the scene, and of course the ending Gungan battle heavily features Jar Jar slapstick. There’s simply nothing in the OT comparable to those Jar Jar scenes. At most you have an Ewok accidentally hitting himself in the face with a sling - a brief joke lasting about a second. At the same time, Phantom Menace has much less character-driven humor than the OT. Obi-Wan arguably has a few funny lines (“we picked up another pathetic lifeform”, etc.), but in general the characters in TPM behave so formally that character-driven humor is very rare.
OT humor was similar to the humor of Indiana Jones: mostly character-driven with a few instances of slapstick. And both featured some dark material. Also, while the MPAA rating system is often an inconsistent mess, in general PG rated movies (like Star Wars and Indiana Jones) have traditionally been considered to be designed for older kids, adolescents and adults, whereas movies made explicitly for 10 year olds and younger are more commonly rated G. So Lucas can claim Star Wars was always for children, but there’s a clear, qualitative tonal difference (especially in terms of humor) between movies like the OT and G-rated children’s movies (e.g. Disney/Pixar cartoons).
Phantom Menace is rated PG, but weirdly relies heavily on slapstick humor more often associated with G-rated children’s movies. This problem is compounded by the cartoonish voice and appearance of Jar Jar and the fact that TPM is the first Star Wars movie to feature a child actor main character. Not that children can’t star in more mature, adult-oriented films (just ask co-star Natalie Portman), but when they do they usually don’t go around acting like an exuberant “Leave it to Beaver” character half the time. If 10-year-old Anakin acted more like Indiana Jones’ side-kick Shortround or even a member of The Goonies, perhaps I would bitch slightly less.
Finally, I also question the historical accuracy of Lucas’ claim that fans complained about C3PO to anywhere near the same extent that they complained about Jar Jar. At least, those scenes in A New Hope heavily featuring C3PO certainly didn’t prevent Star Wars from becoming an unprecedented cultural phenomenon that inspired millions of people to wait in line to see the movie for a 20th time in 1977. Plus, C3PO functions as comic relief much differently than Jar Jar. Again, most jokes in the OT involving C3PO rely on dialogue, not slapstick, despite the occasional instance where C3PO kicks R2 or has his head on backwards or whatever.
