What is the essence of the question to Raban Gamliel, when they ask, "what shall we do," that his father's house was stringent upon themselves, and lenient to the general populace? Certainly the opposite would be reprehensible. But I don't know why the Mishnah would mince words, if it were just praiseworthy, not to say, "it is praiseworthy." Does it imply that there is something reprehensible in practicing more stringency, than one's p'sak to others?
H. David Levine, Roanoke, VA; USA
I would explain the question not as a criticism or praise of the behavior of Raban Gamliel's father but rather as a response to Raban Gamliel's attempt to prove the Halachah from his father's behavior. The sages simply said that Raban Gamliel's father acted differently towards the general populace and therefore Raban Gamliel cannot prove Halachah from him. "What shall we do" is therefore a rhetorical statement: We cannot act like him.
In Pirkei Avos (1:15) we read: "Shamai said, Make your Torah fixed." The Bartenura explains that Shamai maintained that the Psak should be fixed for everyone, without being stringent for oneself and lenient for others. It is possible that for this reason the sages criticized Raban Gamliel's father, since, if he is following Beis Shamai's approach, he shouldn't be stringent with himself and lenient with others.
For further discussion of whether one may be stringent with himself and lenient with others, see Minchas Yitzhak, vol. 1, in his introduction, and see Yabi'a Omer, Yoreh De'ah 6:7.
Yoel Domb