ScienceDaily may be a very handy secondary source. It may be a great place to browse looking for what's been happening lately in the world of science. But if you find something there and feel like sharing it, it's pretty much always best to take ten seconds to find the original source and submit that instead of ScienceDaily.
(I expect the actual reason why Reddit banned it is some sort of spammy malfeasance, which would be sufficient reason even if it were a first-rate purveyor of entirely original content. But, as it happens, it isn't.)