@portland I actually don't think Remora is very good right now because tempo-blue is just a lot better than the Weissman style, heavy mana decks. Basically, the strategy of tapping mana every turn to play spells and cantrip and create threats is just a lot stronger right now than leaving land untapped and holding up counterspells (which has at time been really really good... see Gifts)
But with the printing of cards like Mentor, Preordain, Dack, JVP, Cruise, and Dig among others. Tempo or Turbo Xerox style decks have sort of gotten ahead in the arms race a lot, while Weissman style decks haven't gotten much in my opinion.
I think the Remora goes much better with the sit and wait style for obvious reasons. Although Cronistery Mentor is a thing. I just don't think its quite as good as the straightforward method of directly using that mana to pump out threats and fill up graveyards for the inevitable dig or cruise, I also think that stats prove that. Though I can't really say I would like to play against actual Cron on actual Cronistery Mentor. Maybe without so much Gush, it's gotten even better?
But add to all this, the fact that Fish is just bad against a pretty big portion of the meta... all the creature decks. That's my opinion.