I have worked in the security industry for about 10 years now. The calls we get are either proactive (like yourself) or reactive (an event has already occurred). The bottom line is that many insurance companies provide discounts on your homeowner's insurance for having a monitored alarm. Even if you don't want it for the burglary portion, I would highly recommend that you protect your investment by having fire monitoring (most companies don't provide stand alone fire, you have to have it with burglary protection). So, even if your tenant didn't set the burglary portion of the alarm, the fire detectors should work to call for help (as long as you are paying for monitoring).
A point about SimpliSafe. I understand the appeal that it is a very frugal option and doesn't bind you to a contract. However, just from reading their product lines on their website I can safely say that I would be able to disable that system in less than a minute (and I'm not a burglar). So what then would you actually be paying for? Even if you opt to not go with a national chain like ADT, Comcast or AT&T and opt for a local company, I wouldn't select SimpliSafe (or Vivent for that matter, but thats a whole other post).
As for tenants thinking that the house is unsafe and needs an alarm, thats not the perception. An alarm doesn't make people think a house is unsafe, the location does. The alarm helps people to feel like the home is protected, and the statistics back that up. So my recommendation is to have the alarm installed because it protects your investment. Offer to allow the tenant to use it and give them a code if they include monitoring in their rent. If they decline, then they don't get an alarm code to turn it on/off for daily use, but since the alarm is being monitored the tenant could at least push the panic buttons if they need help and the fire monitoring would be working.
I hope that helps you,
