Wild Unknown did not evoke - for me - the lush feeling of life in the forest that I'd hoped for. It felt more like winter. The Fountain is very pale and icy and too cerebral for me
That makes total sense. The Wild Unknown can have a hard and rather cold feel about it (though some cards are still very "warm" and light !) but I totally see what you mean when you take the deck as a whole. Actually, I tented to find it too "cold" at first, but I warmed to it with use, and now I can access some of its warm qualities better.
And, its true that the Fountain is pale - though I feel it more as being "cool" than "icy", but I get what you mean. Both decks are rather "intellectual" to me, though I find the Fountain easier to access at first glance.
These qualities are not turn off for me, on the contrary, I rather like the decks for these (and of course for the brilliant art on both). I like to have a selection of decks with different energies, different degrees of warmth, different elemental feel, in my collection ; so those the WU fills the "cerebral" section for me rather well, and the Fountain I find to be an "airy" deck.
But I totally understand that you might not like them for these very reasons !