Are homemade smoothies really full of sugar?

I've been having a flask of smoothie a day for a while now as part of eating healthier. I make them myself, just various fruits and a bit of cranberry/pomegranate juice or milk. I keep hearing about how they're bad with the amount of sugar you're really consuming - but surely it's just natural sugars from the fruit and some bad sugar from processed juice? The reason I blend is that I don't really like fruit by itself but can handle it all mixed together.