This is exactly what US did over the years to overcome the "delayed flight" reviews and DOT negative stats. And I'm fine with that. If I book a flight that says it should arrive at 5:15pm, and it arrives within a reasonable time frame of that scheduled time, that's ok with me.
They publish their gate departure/arrival times based on all sorts of factors and if these include anticipated ground delays and they happen to arrive 30 minutes early, then all the better. We were at least given the anticipated schedule before purchasing the ticket so we knew what it could have been under "normal" circumstances with air traffic.
I completely agree. It made/makes schedule planning much easier. And takes the guesswork out of connections most of the time. When I book one of those scary-looking <60 minute E connections in CLT or F connections in PHL I know that, in all likelihood, I'm going to be there in time to hang out in the lounge and take my time, and that it will only even approach the listed connection time in the event of IRROPS.