Complex sentence: On the other hand, solvent system theory was criticized as too general to be useful; it was felt that there is something intrinsically acidic about hydrogen compounds, not shared by non-hydrogenic solvonium salts.
Split into simpler sentences: On the other hand, solvent system theory has been criticized as being too general to be useful. ALso, it has been thought that there is something intrinsically acidic about hydrogen compounds, a property not shared by non-hydrogenic solvonium salts.