Their Alpha* work from DeepMind is actually quite good and has a good track record. LLM/Gemini - yeah, what you said, I wouldn't trust a word their team says.
Aside from the fact you're conflating two very different things comparing this to Gemini, what exactly is the problem with the Gemini?
Specifically just that the release was a bit awkward and had some problems? I've found the latest model releases to be very good compared to other frontier models.
Probably a reference to when Google was widely perceived to rush out the first Gemini release, neglecting to mention it did lots of weird racist stuff.
A Nobel physicist that couldn't do basic arithmetic would definitely raise my eyebrows, but even taking your analogy at face value Gemini was not marketed as fast food slop. Google can't be trusted to hype products in a reliable way, regardless of their technical details.
It's trendy for accomplished people to talk down about themselves as a way to sound cute. It's similar to software developers who like to say "I don't know what I'm doing, I just Google and Stackoverflow all day." It has a certain charm to it, and certainly there are some people for whom it's true, but overall it's just a misguided attempt at being modest but ultimately a horribly misleading statement.
"Do not worry about your difficulties in mathematics, I assure you that mine are greater" - Albert Einstein