Q. Then all your prayers are the same! Just choruses!
A. I'll assume the exaggeration is for the sake of emphasis
I'll assume also that the public liturgy of the Church such as in the celebration of the Sacraments is where you made this observation... And it is true. The texts for these liturgies are very specifically chosen and pretty fixed.
This is in greater part due to experience in my estimation... In her 2000 years, the Church has had many well-intentioned people - even priests and bishops - who have changed a word here or a word there and that has led to a lot of confusion, disputes and even fights to put it mildly. And the last thing the Church wants is a scenario where anyone - one or many - lacks charity in this life or in the afterlife (misses heaven) because we tweaked or allowed someone to tweak a word here or there. That would be a calamity.
So for example some people preached that we don't really need Jesus to save us, we need him for his good example and to make us psyched.
Or that God the Son and God the Holy Spirit were just manifestations of God the Father almost like water that is usually liquid can be manifested as solid or gas.
Or that Jesus wasn't really human like us because instead of a human will like we have, He had a divine will (that of God the Son).
Or that Mary was the mother of Jesus but not the mother of God.
Or that there really isn't anything like sin once you're baptised.
Or if you're saved, you don't need to be baptised.
Etc etc etc.
And the chaos that resulted from these small mistakes is phenomenal! So the Church is very sensitive about what is taught or preached in public in her name. It could be the difference between a soul making it to heaven or missing heaven.
Then there's St. Paul who instructed that in the meetings of the faithful for prayers, there should always be order. That even where a dozen guys were gifted with speaking in tongues, there should be a translator and they should speak in tongues in turn (1 Cor 14). The Church continues to follow that advice.
Aside from the public prayers of the church, there is also the private mental prayer of individuals that one needs to consider... The type that Jesus instructed you should do behind your locked door. This type of prayer has as many different forms and ways of doing it as there are people because prayer is a conversation between friends - Christ and the Christian. And there are no two friendships that are identical.
Also, consider that when the apostles asked Jesus himself to teach them how to pray, He didn't teach them to speak in tongues, or to pray ad lib. He taught them a very specific "chorus", a fixed formula: the Lord's Prayer.
Prayer to God however is not an either/or scenario - speaking in tongues or praying the Our Father; the right leg or the left. It is a both/and scenario - like the different types of foods... carbohydrates, proteins... Each has its place and purpose. Don't belittle or skip one because of the other. Get a balanced diet.
Have a balanced week!
8thMarch 2017