Sadhu does not mean that he is alone enjoying the fruits of his spiritual life. Sadhu means who is trying to make others sadhu. He is sadhu. Krsna likes such sadhu, as He has described in the last portion of Bhagavad-gita, na ca tasman manusyesu kascin me priya-krttamah.
From Srila Prabhupada’s lecture on SB 6.2.12-14, Allahabad, January 17, 1971 (Kumbha-mela)