People are always going to disagree in how something gets done, but I think it's the fact that something does get done which is important here.
We have to walk the walk, if we are to have credibility in persuading others to change as well.
If we have the target date then we have something to aim for and check against on the way to that date. If we don't, we drift, able to throttle back on schemes and projects as suits.
Imo, successive governments like the big grandiose announcements of large projects which tend to fall away, when we could be fixing the things that have real world impact immediately like loft and cavity wall insulation, heat pump migration and having smart meters that are actually smart regardless of the supplier. These are things that tangible in the everyday to people. Fix the things that they can see and touch and you have them onboard for the larger ambitious stuff.