I think it's way too early to declare victory over Facebook or to declare it dead. It might be a good way to fire people about steem, but it feels quite naive when you think about it.
First of all, Facebook are still huge and the steem blockchain is still a drop in the ocean compared to the userbase Facebook is working with. But more importantly, Facebook are putting in a lot of resources and knowledge into keeping their huge userbase engaged and they are already experts at it.
Seeing something new you don't like there should not be taken as a sign of failure, but a sign that they are still working hard on their product. What happened to your post is surely unpleasant for you, but you can rest assured that they'll keep doing it only if it helps then measurably boost the metrics they care about. And the main metric they care about is keeping people engaged and addicted.
The reason your post was marked as spam is probably because to many people tried to scam or down others with something like this.
The average Joe will not get this problem with their day to day Facebook life, so it's unlikely for it to play a part in their downfall. And if it starts adversely effecting the average Joe's engagement, they'll quickly get wind if it and will fix it.
It will just take a lot more than this to take down Facebook.
Additionally, if we want to be realistic about our own thing, the steem blockchain continues to lack an interface that is on par with the functionality provided by Facebook and new users have a hard time getting used to it and shine of them hate it. If we really want to disrupt Facebook, this needs to change. For now, we're only carving out a niche, not bringing down Facebook yet.
Disclaimer: I hate Facebook, I've always had, don't even have a personal account there. I realized I wanted to be on steemit as soon as I was introduced to it.