Riot wanted to remove noob traps, but Cull is the biggest noob trap of all. does absolutely nothing and the gold "gain" is extremely negligible. also Zephyr was a perfectly fine niche item that had no business being removed.
PS: i don't actually care about cull add zephyr back in tho seriously, if wit's end can still be in the game why can't zephyr.
Cull actually has way better sustain than Doran's Blade for the first maybe 15 minutes. Life on hit is much stronger than lifesteal before you have items. Cull does exactly what it's supposed to: reward passive farm lanes. You get it on someone who doesn't want to even try to trade early, and it helps sustain against poke. Take it on someone like Kog, or against someone like Draven/MF when you absolutely can't win trades anyway, and play safely. Finally, it's not a 130 gold advantage, it's 400. You would buy either this or Doran's Blade as your first item, and Cull provides you with 400 gold. Selling Doran's Blade costs you 270 gold in the end. 400 gold is kind of a lot for early-midgame; it's about 15-18 CS you can tack onto your score.
tl;dr it's not a noob trap, you're just not using it the way it's designed to be used. It's for passive laning, not trying to get kills.
Riot's basically said that they couldn't be bothered considering Zephyr into the item equations they were doing. They might change their mind if a lot of people want Zephyr back, but likely not.
It's in the first preseason patch notes where Riot Pwyff writes about Riot's thinking processes. He was hinting that they just couldn't be bothered with Zephyr.
I think Cull should build into an item. It doesn't need anymore combat stacks because it's meant to be a passive item, a farm lane item for the likes of Nasus, Gangplank and every bot lane ADC.
i took cull on anivia and got a huge lead rofl. was fun but i wont do it again. its really only for people that know how to cs... e.g. not low elo.
If they did put Zephyr back it wouldn't have as much tenacity. I do miss the item. Now I really want a boots slot cause you can't really sell your boots anymore.
Zephy was my favorite hide n seek item, now its gone. What do I build after Ardent Censer now? Lichbanes? Zephyrs gave me the MS, the CDR, and tenacity. Hide n seek isn't the same w/o being able to stack Zephyrs.
Zepher was my adc relied on item. Now that they removed it, I'm switching to mages.
Zephyr just needed small tweaks 
now has a single upgrade, i like single items having both AP and AD build paths.
It replaced Avarice Blade, not Zephyr?
BRING BACK ZEPHYR! START THE RIOT! TAKE THE RIOT TO RIOT GAMES!
Shyvana was amazing with Zephyr and Phantom Dancer! Now Zephyr is gone and PD is nerfed. Stinger is the only thing with the highest AS (50%), but only leads to an AP path. Zephyr had a lot of good stuff on it. It had all the AD/AS things you wanted, and it's gone. 
she's angry now, ya know?
[zombie-nunu-bummed] does not approve
