Why then do the Eastern churches confirm(chrismate) infants? Since choice is the big issue here is it useless for them to do this?
As it stands, considering the age confirmation takes place at in the Roman rite, you’re right… it probably is useless to try and force it.
because that is the Eastern Rite, and the OP was about practice in the Latin Rite. as discussed previously in dozens of threads on this topic, which we might wish to refer to if we are going off-topic with the age issue, the ER practice more properly conveys the theology of the sacrament. It is NOT a coming-of-age ritual, or graduation from religious education, or the occasion on which a teen decides to be Catholic. The reasons confirmation became separated from baptism in the west has more to do with historical reasons than with theological, and the differences in how populations were converted, and in different evolution in role of the bishop.
participating in RE and in parish Confirmation Prep is another issue than actual reception of the sacrament, which was question in OP. if you want to discuss that, we also have several ongoing threads for that topic. Canonically for the purposes of the sacraments of initiation anyone over the age of discretion (about age 7) is considered and adult, must be prepared for the sacraments according to age and ability, and must freely chose to accept them.
It is entirely within the parental rights to insist that a minor child in your care attend RE as well as sacramental prep programs, and attend Mass regularly. You cannot force him to accept Confirmation, nor to confess, nor to receive communion. Nor can you or should you pry into what belongs in the confessional.
What is neglected, however, by DREs, pastors and parents, is stress on the serious nature of rejecting Confirmation when it is offered by the bishop. It constitutes rejection of his authority, rejection of the sacraments as instituted by Christ, and rejection of the gifts of the Holy Spirit and determination to conduct one’s life without that divine assistance and in disregard of the immensity of those gifts, and rejection of the opportunity to grow in knowledge of the faith. Very serious, potentially mortal damage to the soul, and by the way, very poor attitude toward one’s spiritual growth and health (and inadequate preparation for marriage, by the way).