I would say it is because SAP's programming environment is rife with business people and very few programmers. 95% of programmers I have worked with were B.A. students who heard that programming pays more, and SAP pays a lot more. I've been doing SAP ABAP for about 10 years on and off. I've worked in both services and product development and have worked in many different capacities, companies and countries.
My background is strong C++, having also worked at high frequency traders and other tech companies writing compilers and schedulers and network messaging systems. Never have I encountered anyone in SAP that would care about security... with the exception of a few BASIS consultants. People are so focused on their small part and fear to rock the boat that is causing it to be the monolithic behemoth it has become. ABAP is an awful excuse for a language that pretends to be a cool 4GL, and the SAP system itself is layer upon layer of bugs, unused code and inefficiencies. One can see a hint of a bright SAP developer here and there, but the way it was finished off suggested they cut costs before everything was full completed (WebDynpro, OO
I worked as a contractor at a bank about 10 years ago. And highlighted the fact that their vendors being able to upload file all to a common directory as the same normal user and password was a huge security issue as well as a client confidentiality problem (as various clients/vendors could read each other's files)... but if I could wager a guess they did nothing about it at least for the time I was working there.
Then there is SAP's resource site (Sap Developer Network), where they are still trying to figure out how to have host aliases and SSO even work reliably. Every time you connect you get a different load balanced host with new host name. The site is a mess and is still struggling to even resemble Web 1.0.
But all this trouble and incompetence is what makes working in SAP a challenge and earns you the big bucks. Not to mention aggressive and plain rude clients sometimes. I prefer product development instead of contracting, that way I feel I can actually do something concrete to help people.