"Bounce to Track" is essentially and in project Mixdown/Export. It does what would happen if you used File > Export except the resulting mixdown appears in a new track (or whatever track you pointed the Bounce to). That means all selected tracks get mixed together into one track.
If you just wanted to export the individual tracks you have to export them one at a time OR in the Export Dialog choose the "Tracks" option (which will show all the individual tracks you have selected and that are now available for individual export). Then when you export a file will be created for each track.
I cannot recall if you have that option available for the Bounce to Tracks procedure as well (perhaps because they are very similar dialogs).
If you want to separate segments of the project (like if there are five songs with a bunch of talking in between each all in long clips) what you have to do is the same as above (select the desired tracks) but before going to the export window do a Time Range selection on the Timeline (drag across the timeline AFTER you have selected the tracks) THEN go to the File > Export dialog (then choose Tracks) and then export. That should create individual files for each track that only span the time range you selected. Unfortunately you can only have on time range selection at once so you'd have to do it for each section you want to export.
Again I am unsure whether those options are available for Bounce to Tracks.
It's just the way the program is designed and it suits usual needs/workflows.
I do however think the Export and Bounce stuff is a little more complicated/fiddly than it needs to be but it does work and is capable of a wide range of export/mixdown configurations. You just gotta read up on it a little. Took me quite some time to figure it all out.
Cheers.