Broodmother: Orchid Malevolence as Core?

So I've been practicing a lot as Broodmother lately and I've found that I really like the hero. I played two pubs with her and completely owned in both of them. For both matches, and pretty much all of my practice rounds, I just built the usual Vladimir's Offering and Orchid Malevolence core. However, I felt that the Orchid was very underwhelming and doesn't fit particularly well on Broodmother. The item is usually for gankers who deal a lot of damage really fast and need mana regen to keep them able to roam. Brood usually just occupies a lane until the towers are pushed and then heads somewhere else to do the same.

Pros

• Gives much needed teamfight presence
• No mana problems
• Slight damage/attack speed boost

Cons

• Still no hard disable
• Mana problems are mostly solved with Soul Ring when managed carefully
• rather expensive for the benefits you get as a pusher
• Not really a good survivability item

I just feel like there are way better items to buy on her instead of an Orchid. As a dedicated pushing Brood I'd rather get to work on my Necronomicon, and as a carry(?) Brood I'd probably want something like a Yasha or a Skull Basher for manfighting. She takes awhile to get around the map unless you constantly put webs everywhere, so I don't see her as a ganker at all.

So am I missing something? Why is Orchid considered "core"?

Orchid is, from what I see, an item with many uses that is good for snowballing because it increases her burst damage while still having utility, and the buildup is very easy and convenient.

I don't really see this item as a core either, but for the highest number of games, I can see it as a good buy. Necro is a decent buy too, but its scarier on heroes that make better use of it, so Brood benefits more from mana regen for endless spider spam, and she does not use the stats as well as say Beastmaster, nor does she have the mobility to use it to the extent of Nature's Prophet.

As for Carry Brood, those items with a BKB and later a Butterfly work well enough (given you're brood, you can snowball these items before minute 35 and be very dangerous) then later tanking or Blink Dagger so you don't get kited to death.

Honestly, if I'm Brood, and I'm snowballing, I tend to get Scythe of Vyse, which provides the same endless mana as Orchid, but a bit more stats, and a good disable and reference to Charlotte's Web.

I wouldn't consider it core, but it's a useful extension in many games - it's really a choice between BKB/Vlads/Orchid, and in what order. Basically it's for if the enemy have a hero trying to counter-push alone, or farm the jungle - with an Orchid and your passives it's pretty easy to take them down, otherwise they'll tend to stun you and run.

It'll definitely stop people from relying on their AOE abilities or getting away easily, plus it does quite a lot for your general damage output.

Necrobook is good, but I'd consider it kinda overkill as you push so hard uncontested anyway, it's situational. BKB is a stronger priority for trying to take rax as you'll need to be able to keep attacking and lifestealing to stay alive.