Yes, glorious anthem effects are useless without any creatures on the board. So are equipment. But they are both very powerful effects in most games of magic because they help you win combat so much. Anthem effects are high picks in regular draft because they're really strong.
As for lava spike, some of the red decks that are basically all burn spells are considered to be kind of combo decks.
And as for spider spawning, yes it wins through attacking with creatures, but a lot of its game plan involves filling up its graveyard and leveraging that zone to its advantage, which isn't something most decks do. How you actually win isn't relevant. Storming into Goblin Warrens actually kills you through turning men sideways, but it's still definitely a combo deck.
See, this is where it feels like the definition of combo is getting too liberal. What I'm hearing is that combo is any archetype that uses any number of unlikely, often underpowered, cards, and combines them such that the whole is greater than the sum of its parts. I wouldn't call that a combo deck, though. That's just an archetype. Or a rogue deck, if you're talking about particularly unusual card choices.
"Filling up your own graveyard" on its own doesn't classify a deck as a combo deck. That's just the theme of Innistrad block, especially in limited. Like landfall was the theme of Zendikar, but running 18 lands and three Plated Geopedes wouldn't mean your draft deck was a combo deck. Again, saying it's unusual, or it's something that most decks don't do, doesn't immediately make a deck a combo deck. In constructed, UB control runs Nephalia Drownyard so that it can mill itself for more juice (along with milling the control opponent out in the mirror). But it's still a control deck through and through, even if no one else is running the self mill angle.
See, this is where it feels like the definition of combo is getting too liberal. What I'm hearing is that combo is any archetype that uses any number of unlikely, often underpowered, cards, and combines them such that the whole is greater than the sum of its parts. I wouldn't call that a combo deck, though. That's just an archetype. Or a rogue deck, if you're talking about particularly unusual card choices.
"Filling up your own graveyard" on its own doesn't classify a deck as a combo deck. That's just the theme of Innistrad block, especially in limited. Like landfall was the theme of Zendikar, but running 18 lands and three Plated Geopedes wouldn't mean your draft deck was a combo deck. Again, saying it's unusual, or it's something that most decks don't do, doesn't immediately make a deck a combo deck. In constructed, UB control runs Nephalia Drownyard so that it can mill itself for more juice (along with milling the control opponent out in the mirror). But it's still a control deck through and through, even if no one else is running the self mill angle.