If you are praying the Divine Office/Liturgy of the Hours, you are definitely doing the right thing because you are praying the daily prayer of the Church.
I take it your friend is not Catholic? So he doesn’t understand the concept of communal prayer. For him there’s only one kind of prayer–personal. Personal prayer fine and just as important, but praying the Hours certainly isn’t being a parrot. How can reciting the Psalms, the holy word of God, be a bad thing? How could God be “offended” at that? No, it’s simply that your friend doesn’t see the benefit of recited prayers.
For those who faithfully pray the Hours, it is life changing, as you must know. We are praying with the whole Church, we are praying God’s word, and we are not focusing just on ourselves, our feelings, our needs, but on what is best for all the baptized.
The Hours lead us through the Church year, helping us focus on the various aspects of Christ’s Incarnation. There’s nothing rote or dead about it. Challenge your friend to pray the Hours and then come back and tell you they’re of no benefit. I’d bet he wouldn’t be able to do it.
Also, if we rely on “off the cuff” prayer all the time it too becomes rote, doesn’t it? And too insular. I’ve listened to so-called spontanteous prayers that take the same form every time. They start with “Father God we just want to thank you…” and go on with the same old petitions and the same old words in the same old way. Praying the Hours gives us a greater palette of intentions, of points of view, of spirituality and theology. It’s never the same twice, even if we are reciting the same Psalms as a month ago. It remains ever fresh because it is God’s word and not merely our own thoughts and intentions.