Except the time it took you to research, install, validate it's running, and do general upkeep. Also doesn't help you if you're on vacation with limited internet service.
Yes you can set this up yourself (and spend a lot more on the hardware, which they generally give to you pretty cheaply or even "free" because you're signing a contract) but when you go hiking in the mountains and someone uses your Facebook posts as a cue that you're out of town, you're SOL.
Don't get me wrong I love looking at all the home security stuff you can do, and it does indeed sound like a neat project. But you're really paying these companies for monitoring and automatic (human) response, not the security systems themselves.
So true, my dad has a monitoring system he built and he constantly looks at his phone as a deer or bear or something triggers it. I'd imagine the lost productivity for people who depend on the flow for work would be immense.
In an area without Internet service, for me, it is common to miss calls as well. Plus, from personal experience, the security company will not notify law enforcement until they have called you to confirm it is not a false-positive alarm.
In my case, before the alarm goes off due to a forced entry, I will have automatically received notifications with snapshots of people around my property. Even if the security company had called immediately, a response would take >10 minutes. So I just self-monitor.
Overall, with home security you basically just want to be a more annoying, harder target than your closest neighbors. It's sad but true.
(Arguably, these discounts are things they trust you at your word for, but perhaps if they're not satisfied they're true during a claim, they might use it as a reason to not pay out.)
Also, the discount is for central monitoring, not merely having a system.
I'd reread your paperwork if I were you. It sounds like you could have falsified information, and effectively have no insurance.
Alarm.com has built some of their own hardware, but their operation is obviously much smaller than Nest. Can they still compete?
Call yourself BEU Security.