I occasionally get emails from commercial reprographers who print DWF files for clients. They are surprised to see what they refer to as "spiked text."
Believe it or not, this is not Halloween Party invitation. This is expected behavior. AutoCAD allows line joins to be set as mitered.
Setting a line join style of mitered results in wide lines that look like:
Alternatively, setting a line join style of capped results in wide lines that look like:
Plot styles in AutoCAD can be set to treat text as geometry. If this is done in combination with a line join setting of miter, you can get "spiked text." When drawings are published to DWF, those settings are obeyed.