I liked your answers (in Insights). I just wanted to offer another one. Rav Ya'akov writes in Emes L'Ya'akov that he thinks it is because Kalev was married to Miriam and thus her influence would protect him from the Meraglim. Lots of other examples in Tankah of wives influencing their husbands (this week's parasha of course, one of the very first Rashis). Anyway, just wanted to share.
Matisiyahu, Clifton, NJ