Ok, I am sorry, I meant to say that it is a practice that has not been in use for quite a long time, to the point that the Sacred Congregation for Divine Worship writes in 1969 and refers to reception on the hand as "the new manner of giving communion" and to the previous one as "the traditional practice".
As for "advisable", I was referring to this quote:
In reply to the request of your conference of bishops regarding permission to give communion by placing the host on the hand of the faithful ...] The Pope grants that throughout the territory of your conference, each bishop may, according to his prudent judgment and conscience, authorize in his diocese the introduction of the new rite for giving communion. The condition is the complete avoidance of any cause for the faithful to be shocked and any danger of irreverence toward the Eucharist. ...] The rite of communion in the hand must not be put into practice indiscriminately. ...] It is advisable, therefore, that the rite be introduced gradually and in the beginning within small, better prepared groups and in favorable settings.
It seems to me - just my impression, of course - that the Holy See underscores that reception on the hand is something to be addressed with great prudence, both due to the negative impression that can cause in the eyes of some and due to the possibility of the Eucharist not being treated in the most proper way. Communion in the hand is not forbidden, but the traditional way may appear advisable in that it does not carry all those additional complications.
Anyways nowadays this is such a widespread tradition - at least in the US - that there is not much point arguing about it. What I do not like is this: the Church allows us to receive on the hand in addition to the traditional way, yet often the new way is taught as the standard way. I do not understand why. I see no reason for this new way, nor for it to be adopted as the standard way. I feel that kneeling places an emphasis on humility and makes Holy Communion more solemn. I wish to learn more about this, perhaps in another thread...