Actually that would be critics of Catholicism. You have to read pretty selectively to reach that conclusion. It's easy to gloss over words like "good" in "a good confession" or "a good rosary." It's easy to trivialize the commitment, which is an internal thing, of others.
Yet in another sense there is SOME truth in the criticism. God is in certain sense external, though not in the more important senses. And we do trust Him to work through sacraments. And I would venture to say that may of the "internally" committed would testify that on a day when things were as dry as the Baca Valley they looked back and found that it had been a place of springs after all. (Ps 84)
The Apostle Paul said, "the kingdom of God is not meat and drink, but righteousness, peace, and joy in the Holy Ghost."
Those who truly experience the "new birth" Jesus spoke about, experience the "resurrection power of Christ" within them. God takes up residence in us, we become His temple.