It is a valid concern that Occidental is in the uncanny valley for Romance language speakers in particular. However, see this quote below:

The "Uncanny Valley" is much the same as what I've called the "Rube Effect": a feature of a system that makes me feel illiterate for using it. [...] My point was that if there is a slight resemblance between the new system and ones already known, you can accept it as coincidence and use it as a mnemonic, but if the resemblance is great, then any deviation will be perceived as an error.

Thus the "Romance" aspect of Esperanto is fairly low, so it doesn't bother me when it does something non-Romance. But when Interlingua does something non-Romance, such as not having multiple negation (which Occidental does allow), it not only seems wrong, but almost deceptive: I feel set up, taken in by its Romance appearance. Because Occidental doesn't look entirely Romance (the pronoun "it," past tense in -t, "lass," "mey," etc.) I may find it annoying, perhaps, but I don't feel deceived.

I once wrote that when you visit Interlingua, it answers the door in a Romance mask, ushers you inside, exchanges pleasantries, and goes to get you some tea. Then it pours the tea on your head and reverts to the mask. "Is something wrong?"

When you visit Occidental, it resembles some Romance languages you've known, but it looks more like a creole of Romance and English. It almost immediately slaps you in the face, says, "I'm not Romance," and then invites you in and is a gracious host. In other words, it establishes independence early on, and you either accept it or leave. Interlingua maintains a Romance guise most of the time, only to do something really alien when you aren't expecting it.

This is why I kept seeing native speakers of Romance languages trying to fix Interlingua: when you try something that seems odd, even though the grammar may specifically permit it, you're wrong. You cannot really say "Ille vide me," even though it's technically allowed (it is completely acceptable as "Il vide me" in Occidental).