Someone asked me this the other day, and I couldn't think of a good answer. Platform portability is completely irrelevant to the project.
In fact, Jet has some features that SQLite does not, namely foreign keys.
So can anyone think why SQLite should be used instead of a Jet database?
Contrary to what other people are saying, Jet is not dead and far from it: ACE is the new version of Jet and it's pretty robust and backward compatible.
Both SQLite and Jet/ACE have their strengths and weaknesses and you need to get more information about the specific points that are important to you and your application.
People who say that Jet corrupts databases are stuck in 1995.
In the end, unless your application has some very specific requirements that are pushing the boundaries of either database engines, then it probably doesn't matter which one you chose.
Just use the one that easiest for you to include in your project.