Lukas Eder just posted a note about when to use a framework: http://blog.jooq.org/2014/03/05/when-to-use-a-framework/
I totally agree! And I think it is not only limited to big frameworks like JPA/Hibernate.
Often developers spend a lot of time evaluating a library that solves their problems. But sometimes it would be easier to write a few lines of code to solve the problem.
If you do it your self there are two advantages 1) you better understand the problem because you solved it on your own and 2) your solution is exactly what you need. There are no dependencies to a big framework or library that may have their own dependencies etc.
For sure my idea does not scale. If your problem is O/R-mapping it doesn’t make sense to create your own Hibernate. But if you just need some small utilities – why not think about…