Start by reading the InDesign Help section on opening PageMaker files. It suggests some steps to do IN PAGEMAKER BEFORE you do the conversion:
•If the PageMaker file or its linked graphics are located on a network server, floppy disk, or removable drive, it may not open as expected if an interruption in data transfer occurs. To prevent data transfer problems, copy documents and their links to the hard disk, preferably in the same folder where the PageMaker publication is stored, before opening them in InDesign.
•You may want to use Save As in PageMaker to clear unnecessary hidden data.
•To ensure that all links are maintained, copy all linked files to the same folder where the PageMaker publication is stored.
•Make sure that all necessary fonts are available in InDesign.
•Repair broken graphics links in the PageMaker publication.
•If you have a problem converting a large PageMaker document, convert portions of the PageMaker file separately to isolate the problem.
Looks to me like your file didn't have real text but placed graphics instead.
One very important addition to Steve's list. The graphics must be linked.
Embedded graphics will not make it through the conversion. Unembed them in Pagemaker before conversion.