This is absolutely not true for Latin Catholics. Kneeling in your tradition shows reverence, awe and adoration, and supplication. Think of the words to O Holy Night: " Fall on your knees, oh hear the angel voices, O Night Divine…"
I have often heard this, and I have always found it a bit perplexing when it comes to Eastern Catholics in the West. If we ignore the Eastern Catholics who are (first, and perhaps second, generation) immigrants from countries with a Eastern Catholic culture, most Eastern Catholics in the West are part of, an have grown up in, Western culture. In the West, not only in the Church, but also in the larger culture, kneeling – as you point out – signifies reverence, awe and adoration, and supplication. Eastern Catholics in the West are also part of this culture. I know some Eastern Catholics, some of whom are converts or who have switched rites, and I simply cannot understand why one would claim that kneeling doesn’t signify reverence, awe and adoration, and supplication for a Eastern Catholic person who is in every other respect western.
This is one of the many reasons why I will never be eastern (should I become Catholic), unless I happen to move to an eastern country. I am convinced that the faith grows much better if your liturgical life has a (somewhat critical and counter cultural) connection to its surrounding culture.
This is also why I am in favour of letting Orthodox christians who want to develop western liturgies (and to follow the calendar appropriate for the country they are in) do just that. If I were Orthodox, and living in Norway (which I do), I would be in favour of celebrating Christmas on December 25 after the Gregorian calendar. Norway is culturally western, after all. And in Norway that day is also a public holliday.
