That's not true. As soon as anybody decides to do anything, they are exercising free will. We discipline our children for hitting others, throwing tantrums, stealing, not sharing, etc. constantly and these are very young children who technically "don't know better".
There is a whole order of magnitude of difference between a toddler who won't share his toys in the sandbox and one who cheers and celebrates when innocent human beings are tortured and killed. Amalek needs to have happen to it what it wishes on others, regardless of age.