They can bring some nice benefits like remote starting in cold (or hot) climates, but there needs to be much better design to minimize the exploitability of these systems.
We had remote starters in the 80s, they didn't need Internet access, they were a completely local wireless solution, just like old wireless garage door openers.
Remote starters that can reach from inside an office building to a distant end of a parking lot are underrated. I had this for about 6 months before the 3g network was shut down. Now, I'm limited to the range of a keyfob.
Not to mention scheduled starts: say, 10 minutes before you have to drive to work, to make brushing snow off a car much faster, or 10 minutes before you leave work so you don't give yourself a good sear on a random piece of metal in your car in the middle of summer.
It's not a thing a car should require, and even for nice-to-have value-add features, it should be tightly secured, not only from external access but from the manufacturer.