Clone Wars was very hit or miss and burdened with all the flaws inherent in the prequel trilogy's subject matter, but it actually managed to pull some decent stuff at times.
Clone Wars was very inconsistent in tone, but Rebels is extremely biased toward being a kids show rather than "all-ages" entertainment. Personally, I found clone wars much more tolerable.
Here's the issue with the Clone Wars, that I'm pretty certain many of the adults may have missed. At time, the Clone Wars was so far away from being "all-ages" that it isn't even funny to me. The way they upped the violence was terrible. It went "mature" in the most immature way.
Yes, Rebels does have a few episodes that have skewed toward standard kid fare. The first season isn't perfect. But neither was Avatar the Last Airbender or Gargoyles or Batman TAS.