It shine for business apps (aka: the most common of it).
Is more "batteries included" than python. You can do a full app with just Fox, because it include reporting, database, database designer, form builder, menu builder, OO, procedural, SQL, a really good grid. Seriously, I have only know of 2 great grid controls: The VFP one and the DevExpress for Delphi one.
Have a truly good grid was something damm useful. Manipulate data was easy, you could make a app only around the grid!
But all of this included.
And this could be made to work for the end user. So, your reports could be designed by a end-user. Or build forms. Or menus. Similar to lisp where everything are the "()" in fox everything was a table. A form? a table. A report? a table. A class? a table (if designed visually. You can make everything in text like a regular program too).
You can make dynamic the whole app if the developer learn to use the language fully.
Was also relatively easy to grasp. A power user could work on fox with a dozen of commands (and remember: The grid, like a excel spreadsheet, was enough for a lot of task), but in contrast with acces, you can "upgrade" the mess to be more professional.
Is simple for a programmer, too. My first programming class was with foxpro, and at the end of it we have made a FULL app with menus, forms, tables, reports and mini programs.
The closet thing today? Perhaps the django admin, but it is far less powerful and constrained.
The weak of fox was that MS prefer to push Acces (and both fight for the same kind of user), it neglect the DB engine pushing for sql server and, well, neglect the language.