You're right to be disappointed, because you put a lot of time into making something you hoped would be appreciated and loved. BUT . . .
Some people just don't have a special place in their heart for quilts (or afghans or wallhangings or whatever the gift may be). I've learned that I make them only for people I know will love them like I do. If I make one for someone who isn't a quilt lover (or if I don't know for sure that they are), then I'm taking my chances, and I can't be disappointed if they aren't overly excited when they get it.
My niece loves my quilts - and she even made one for her daughter's "big girl" bed, but she didn't want one for the girls when they were babies. Instead, she preferred my lightweight knitted afghans that were easier for them to drag around behind them as they got older. Baby #1 is almost 2, and that afghan is still her favorite. Baby #2 is about 4 months, and she doesn't have hers yet, but it's in the works.
Baby #1 came over about a month ago to spend the morning with me. I have an old baby quilt that I actually put on the floor for the pets. It has a hole in it, and it was nothing special to begin with - just a practice piece for quilting. Anyway, Baby #1 took a liking to it and would lay on it to watch TV. When one of the cats came up to lay on it, Baby #1 put her hands on her hips, looked down at the cat, and said, "MINE!" So, see? Even if Mom wasn't as appreciative as you would have liked, the baby may make the final decision after all!