On page 44 of  Flanders writes "A treatment from this point of view of exterior calculus which is not quite completely satisfactory and which unfortunately is embellished with historical comments often in bad taste is found in Blaschke." His reference is Baschke's book  as listed on page 197.
What comments did Flanders think were in bad taste in  and what/why did he consider Blaschke's presentation an unsatisfactory treatment when compared to his?
 Flanders: Differential Forms with Applications to the Physical Sciences, Dover Pubs. 1989,
 Blaschke: Einfuhrung in die Differentialgeometrie, Berlin 1950.