Uh, no. Not at all. As a matter of fact, the two video clips I post below are remarkably moving testimonies about how profoundly important those hymns can be...for children!
Check 'em out.
Item 1) Modern hymn writer Keith Getty, in this fascinating 4-minute vidcast, talks about Cecil Frances Alexander, a musician who, two centuries ago, "realized that the music of her time was beginning to lose its focus and quality. Fearing that this decline took away from the heavenly glory we are meant to revel in, she made it her mission to bring new inspiring and faithful music to her worship community. She wanted to present young people with songs that encourage them to have big thoughts and greater understanding about their faith."
Item 2) Joni Eareckson Tada talks about her deep gratitude for her parents teaching her the great hymns of the Christian faith when she was a young girl. She does so in a remarkable moment when she joins the Getty family in their ongoing family hymn sing. The whole event is inspiring and fun but you'll find Joni's testimony (just before she joins the Gettys in singing") at about 8 minutes into the clip.