Spears would suffer from cavalry charges. What makes the pike different is that it's butt end is grounded and then the pikes are leveled in a hedgehog bristle. Spears might have a bit of reach over swords but the weapon is still only held by the spearman and so a horse charge will still penetrate the line.
Not all pointy ended sticks are the same in use or effect.
With pikes, the weapon itself absorbes the impact and transmits it to the ground so it forms a real barrier.
With spears the man still absorbes the impact through the weapon and suffers the direct shock of the charge.
Cavalry has always been powerful and decisive on battlefields. First, prior to impact charges, by being able to quickly flank infantry and out manuvere foot soldiers.
After the development of impact charges, foot soldiers would often run at the mear threat of a horse charge.
Pikes gave the footman some hope of success but foot soldiers were still subject to being out manuvered by horse and forced to defend either from an infantry push from their front, or horse impact from rear or side.
Also for pikemen, the weapon itself would often inflict casualties on themselves or their fellows by becoming ungrounded and shoved like rams through the ranks by the impact of the horse charge.
Anyway, that's my limited understanding of the issue.
Bookmarks