Quirrell sometimes makes the mistake of pushing people too much. Perhaps as a consequence of too much cynicism. Harry would probably help Quirrell just because he cares about him… but Quirrell does not understand the concept of “care” and thinks it is only a role that Harry feels obliged to play, which he does not trust as a sufficient motivation to overcome obstacles. So he add further motivation; things that seem sufficiently motivating in his model of Harry.
Quirrell sometimes makes the mistake of pushing people too much. Perhaps as a consequence of too much cynicism. Harry would probably help Quirrell just because he cares about him… but Quirrell does not understand the concept of “care” and thinks it is only a role that Harry feels obliged to play, which he does not trust as a sufficient motivation to overcome obstacles. So he add further motivation; things that seem sufficiently motivating in his model of Harry.