It doesn't do everything and there are some people who have one who think it should do more. But one good reason for not incorporating a turbo timer is that in some states they are technically illegal but mainly because under most conditions they aren't needed.
in my job i can drive very long distances , i wont say tank to tank , but sometimes a tank in 2 stops , its not good to shut off a turbo engine after running 4 hours @ 100 ks in a second , as it is now ill get out and have a smoke and walk around for a few mins before i turn it off , point in mention this truck is 6 weeks old and done 15,000 ks , you get where iam coming from