It's not that SSIS is difficult, it's just that's limited by it's graphical interface and some/much of the original design hasn't been fixed. (Sometimes it is not intuitive and a bit of a straitjacket.)

Imagine if you couldn't write TSQL and all you had an early version of Microsoft's Expression Builder feature. Or you only could use DOS style batch files for automation instead of PowerShell. That's how programmers feel about being limited to only SSIS.