rsync has a few quirks. scp is more-convenient for many people because it shares almost identical options to cp.
The most frequent cause of grief with rsync, in my experience, is presence or absence of a trailing / on the source argument. Many users aren't even aware of the difference in meaning, and even those that are aware still get it wrong sometimes, primarily due to tab-completion.
I personally use rsync frequently, but for newer users I recommend scp, unless they're dealing with a very large volume of data where rsync would provide significant benefit.
The most frequent cause of grief with rsync, in my experience, is presence or absence of a trailing / on the source argument. Many users aren't even aware of the difference in meaning, and even those that are aware still get it wrong sometimes, primarily due to tab-completion.
I personally use rsync frequently, but for newer users I recommend scp, unless they're dealing with a very large volume of data where rsync would provide significant benefit.