I suspect a lot of it comes from the natural desire for humans to be recognized as "successful" by their communities. Society normally does this by easily-observable "markers" of success (in the community, educational achievement, military rank, corporate rank, etc.)
- Being elected by their community to represent their interests (not allowed by JWs)
- an advanced degree, thereby demonstrating their intellectual success (not tolerated by JWs)
- rising through the military ranks (not allowed by JWs)
- rising through the corporate ranks (lowers your "success" within JW community)
- providing well for your family-- nice home, nice cars, nice clothes, etc. (discouraged by JWs)
Almost every normal "marker" of success in society at large is either discouraged or forbidden by JW doctrine. I suspect it causes a lot of JWs to focus too much on the spiritual success markers-- namely titles. I've notices that some brothers/sisters who struggle to succeed in everyday life ways are often the most intent on achieving JW titles...and not letting those around them forget they have them.