I don't really like to defend SAP, as I had to use it once just for putting in working hours and was horrified by the necessary steps to do so - but afaik SAP is not "terrible pieces quickly thrown together ".
It is rather way overengineered. In such a way, that freshmen to SAP(out of university), get assigned to a project - but for one whole year are basically just have to walk along with the team, without contribution actual code, because they have to understand how it all works together first.
(at least thats what I've been told by some people going there)
Sounds glorious and horrifying. I rather did things where I saw actual progress and impact of my work.