They've been ETA mechanicals forever. Don't think in-house movement is what Panerais are famous for. Some love their history; although they allied with the "bad" side. Their pig submersible are still liked.
Not everyone can afford a Patek/A. Lange & Söhne/AP/etc. I used to splurge on timepieces but never achieved the higher end. Pannies are great starters, IMHO. Seems the in thing now is sports watches again (Aquanaut, Nautilus, Daytonas). I still like the looks of grand complications over those aforementioned ones.
But this watch snobbery is like high end audio, wine, cars...etc. It's just subjective; unless someone in the old Italian navy did hurt someone in your family.
ETA make perfectly fine movements. They are solid and reliable. I have no problem with a watch having an ETA movement. The issues with the Panerai using ETA movements are:
1. It is advertised as an in-house movement, when it is not. Only one word for it: SCAM.
2. There is no extra finishing of the movement. Tudor watches use ETA movements as well, and even at their lower price of $5000 they still take the trouble to refinish it.
3. It sells for $30,000. That is an obscene price for a watch with an ETA movement. For context, you could get an entry level Patek or a Lange for that price, not to mention Jaeger, or even H. Moser et Cie. All of these have genuine in-house movements.
And let's not forget that the watches are so poorly made with off-the-shelf movements that forgeries are easily on par with the real thing. In fact, the forgeries are so convincing that Panerai's own social media marketing have posted several forgeries on their official Instagram account. Oops.
I would be perfectly happy to buy a Panerai if it sold for $5000 and advertised the watches as having ETA movements and provided the same level of quality as other $5000 watches. But it does not even compete with Tudor in terms of movement finishing. I have an Omega Aqua Terra which I wear daily. This has an Omega in-house movement, is nicely finished, is solid and reliable, and it sells for ... $5000.