Daf Yomi - Sukkah 18 - Abbreviating Taharos by David

Tosfos q.v. “ain” asserts that the custom of the gemara is to abbreviate references to taharos. Now Rashi on 14a states quite to the contrary, that the Gemara seizes the opportunity to elaborate on mishnayos that deal with taharos. Granted one can distinguish between elaborating upon a mishna already cited ( the case Rashi deals with) from simply citing to Tahraos, but nevertheless, Rashi and Tosfos do appear to articulate two different viewpoints.