I thought every standard pickup on the MIM P's were abismal. Sounded like S**T. They use ceramic magnets. I replaced every pick up I owned (MIM P) to Fender Original '62 or Duncan SPB-1 Both alnico 5 design. Big big improvements to my ear and judgement. By the way alnico is a magnetic material made of Aluminum, nickle and cobalt. Ceramic, I am unsure of. Some baked compound maybe?
Possibly it's more just the ones you heard? MIMs do tend to be all over the place when it comes to tone (and weight!) based on my experiences with them. However, I have a 2014 MIM PB where the stock pickups sounded just fine. And I've got many years of playing bass and easily over 100 different PBs (MIA, MIM, and MIJ) I've played during that time to compare it to.
Dunno. Luck of the draw maybe?
By the same token Alembic and Gibson have both used ceramic magnets in some of their pickups with excellent results. As had the legendary Bill Lawrence with some of his. So I don't think there's anything intrinsically wrong with ceramic pickups per se.
A magnetic field is a magnetic field. The differences are found in the focus, strength and geometry of the field and not the material itself - which is where good pickup design comes into play. As any knowledgeable pickup designer will tell you, there's a lot more to pickup engineering than just what type of magnets are being used.
There's no such thing as a "tone magnet." At least not yet...although I'm sure some marketing guy will eventually get around to making that claim. (You heard it here first, folks!) Hmm...I smell profit opportunity. Now where did I put that link to form your own Delaware corporation for $100?

Life goes on. It's all good.
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