Skarlock,
I did a little more testing this morning and can replicate your results. Some observations:
Typically when fonts become 'fuzzy' that is because they have been converted to an image. When I created PDF files with Pub 2010 and 2013 with an inserted Excel object from Excel 2003 the text was 'fuzzy' in the 2013 version. Furthermore it appears the file
was 'flattened' as I could select text in the Pub 2010 pdf file but I could not in the Pub 2013 pdf file. I am using the FoxIt reader instead of the Adobe Reader. Foxit also has a 'Text Viewer' option. It shows text in the Pub 2010 version but no text in the
Pub 2013 pdf version. Both these tests seem to confirm that text had been converted to an image in the Pub 2013 PDF.
I also noticed that the file size of the two PDFs varied considerably. The 2010 PDF was ~99 KB while the 2013 was ~55 KB. This also suggests that the 2013 file was lower resolution which also explains the 'fuzzy' low quality text.
Now the question in my mind is has Publisher been changed or has the PDF tool? I do not have any other Office 2013 programs installed. Would you please import an Excel object into a Word 2013 page and create a PDF and compare the results with Word 2010?
Perhaps create a pdf directly from Excel 2010 and 2013. As I said earlier I actually used an Excel 2003 object for my testing.
Do you get a lower quality PDF file from other Office 2013 programs or is this unique to Publisher?
What PDF reader are you using and can you select text from the PDF created from Pub 2013 and Pub 2010?
Do you also note the file size discrpency in the PDF files?
DavidF