Wikipedia is not a source. It is not even research literature. Just an opinion of some ... guy? We are referring to the battle of Hastings, aren't we? Well. First of all: This marks the beginning of the Middle Ages in Britain. It just can't stand for THE Middle Ages. Do you know where said shield wall was located? Do you think this is a good example for the frontal charge of knights against foot soldiers?
1. At first the battle of Hastings and now Bannockburn?! From 1066 to 1314? What about the quoted "cavalry supremacy" in between?
2. The Battle of the Golden Spurs. Consider the terrain. Consider the aftermath.
3. The battle of Bannockburn. Consider the terrain. Consider the commanders on each side. Consider the situation at all. And then we can talk about the beginning of the loose of cavalry supremacy in the Late (!) Middle Ages.
My points as well: You need discipline and well trained soldiers to beat cavalry.
You need an able commander.
In most cases (in all you quoted) you need the terrain on your side.
Let's have a look at:
Crecy.
Discipline. Checked
Professionals. Checked
Commander. Checked
Terrain. Checked
Terrain. Double Checked.
Use a well organised army of able soldiers, use proper tactics and use the fricking terrain.
And why do you think Scottish, Swiss and German soldiers didn't just stood very tight to wait for the charging horses but used these very long pointy sticks?
Why do you think the tightly packed Hussite fanatics waited not just behind their pavises but inside a Wagenburg for the crusaders to charge?
Yes, cavalry was very able to be beaten by proper tactics. But even in early modern times these were crazy guys on highly trained horses. A stampeding bunch of horses would nearly do anything to continue pressing forward.
At last a little delicacy for those who say a horse wouldn't do these or those things:
A horse would do nearly anything if trained to do so.