ROB
The Gemorah in Eiruvin Daf Vav Amud Beis states openly one who grabs the Kulos of Beis Hillel and of Beis Shammai is a “fool”. Rather if one wishes to follow BS they must do both Chumros as well as Kulos and if they follow BH they must do both Chumros as well as kulos.
In English its termed “intellectual honesty”.
And the term “Koach D’heteirah Adif” is commonly understood to mean that it is harder to be meikel since once must have an ironclad “sevara” or Kabbola while anyone who is in doubt can be machmir. See Rashi in Kesubos Dav Zayin Amud Aleph who seems to be following this understanding.