1. Sensors dramatically increase the acquisition cost for a policy.
2. It is unproven that sensors will mitigate losses. We all see the potential but there just isn't data there to tell us that.
If I could prove #2 then #1 becomes simple math, if the CBA is there then incumbent carriers will adopt it. It's just not there yet to justify doing outside of startups and market tests.
3. When carriers pick a partner and get into the preventative game then there's some liability that opens up if things go wrong. One could argue that the carrier is already covering the risk - this just means the preventative offering has to line up with coverage being bought.
4. Last but not least, the biggest source of losses is CAT related in property. Sensors will get at the second tier water and fire - again loss avoidance has to justify the sensors unless the preventative side is an ongoing fee service.