Completely agree on Atma's. Not really any champion out there that wants armor and critical, except for an ADC (who is needing some defense, likely due to a 3x or 4x AD threat enemy team).
And a carry who is in that position is better served with a Randuins, because it also gives some health, and a great passive for denying enemy AD champs.
Switching it to AD/Armor (with its passive intact) would just make it grant too much AD, though, so attack speed would work well (since most fighters benefit more from aspd than crit%.
Executioner's Calling is just bad. The champion that it is strongest against is Mundo (a tank with insane regen), and it still doesn't see any professional play, despite the frequency of Mundo picks. Exactly for the reason stated - no upgrade path, and crappy slot efficiency. Mundo is a late game champion, so an item that wimps out after mid-game is pointless.
The problem with Youmou's is that the other half (Brutalizer) is insanely powerful in the early game (flat pen and flat AD). And the completed item's active is insanely powerful (not OP, but compared to Brutalizer + Avarice, Ghostblade is insanely strong). So there's really no scenario where you have an Avarice in your inventory for more than one trip out to lane, because you'd have to be crazy not to finish the item.
1 lane trip is usually 5 minutes or less. 5 minutes = 90 gold from passive, plus up to 126 gold from minion slaying. So, best case scenario, its saving you ~200 gold (and, usually, far less than that).
Which leaves Staikk Shiv. Here is an item you can rationally build Avarice on first. Zeal is nice, but not a huge power spike. Zeal doesn't give AD, so you're not forfeiting anything there. And its early game, so you don't have any crazy ADC multiplicative stats hitting their peak yet (so that crit% is fairly weak).
But that early game scenario is exactly where Shiv goes wrong. Shiv and PD fill the same general item slot, with Shiv having an early game and split pushing advantage, while PD is more of the lategame max dps item. Or, in other words, 6th item PD = good, 6th item Shiv = bad.
What that means is that if you build an Avarice Blade to turn into Shiv, just like the Ghostblade, you're pressured into upgrading it, because Shiv provides something major to completing your goals.
So, while you're more likely to have an Avarice Blade sit in your inventory for a while if Shiv is your goal, its still an item that you're rushed to upgrade.
So, how this bothers me:
Every other gold item in the game has 3 tiers. Tier 1 is a "meh" gold generation item, designed for supports. Tier 2 is about twice as good as the tier 1. And Tier 3 adds another side item in, and an activatable item, but still holds onto its gold generation.
Avarice blade is a tier 2 item with tier 2 gold generation (or tier 1.5 maybe). This is cool. Giving ADCs/fighters a tier 1 gold gen item could be really bad. But when you upgrade it, no aspect about it having been Avarice is kept. No passive gold. No gold bonus for farming.
And you're actively pushed into upgrading it, because the (useful) items it turns into have amazing actives/passives.
So, in all honesty, the item simply shouldn't exist.
If you're going to have a farm-centric item, it should continue to have a farm incentive when upgraded.
If you're not going to have a farm-centric end-tier item, don't make the mid-tier one upgrade into anything, and give it better numbers.