Jennings is no less boring than Trebek, but really, this type of game show is more cerebral than every other show and doesn't need a host to take over the show with his "personality". This format requires a host to do his/her job but otherwise stay out of the way and let the contestants make the show happen. Jennings does this.
I didn't say Bialik wasn't cerebral - she's clearly very intelligent - I said the show itself was cerebral and didn't need an over the top personality. Indeed, this show works best with subtlety. Imagine the train wreck if Steve Harvey was given this show..
Jennings is a decent mix of charm and subtlety, plus he's got the pedigree of the game. Bialik may have a pHd, but she wouldn't have a chance against most good contestants.
Regarding politics, I assume that Jennings and Bialik are on the same side of the isle.
KJ definitely has that perfect combination of subtlety and charm......and I'll add: TIMING. And yes, his job is definitely to stay out of the way, keep the game flowing and maybe even bring the best out of the contestants. One of the things I like about Jennings is...he is SO damn smart, you can tell he knows all the answers himself, and sometimes makes funny quips tying the answer to the question with something he may have learned about the contestant. It takes a host who is very quick on their feet to be able to do that on the fly. KJ is great at it, and he makes something difficult like that look easy.
Bialik was fine, and she's likeable. But if the show wanted continuity after Alex, KJ was definitely the right choice. Like you said, the show itself...and the contestants are the stars here, not the host. Whereas....on a show like Family Feud, the host is the star.
I will admit that when they were running through guest hosts after Alex's passing, Jennings was sort of low on my list, but as I've been watching, I realize with every passing game that Jennings was the right choice after all.
His timing is indeed good, he does ad-lib well, and he mostly stays out of the way. I wish his voice was better modulated perhaps but I'm glad he's the permanent host now.
"Mayim is extremely cerebral: 'BS in neuroscience and Hebrew and Jewish studies, as well as a PhD in neuroscience from UCLA.'"
Counting up college degrees and where they came from is a classically uncerebral approach to gauging someone's intelligence. "It is as possible for a man to know something without having been at school, as it is to have been at school and to know nothing." --Henry Fielding. If you don't know who Fielding was, I'm not surprised.
Opinions vary, but I don't know if a more PERFECT replacement could have been found after Alex passed. IMO, he has the exact PERFECT chops for that specific role.