Because the Gig Performer world is the Gig Performer world. Different views 
For example, although switch from 4.5 to 4.7 seemed small in terms of numbers, it was HUGE in terms of included features!
In the Gig Performer world, lots of hardenings and possibly complete overhauls are happening behind the scenes.
Sure. If you don’t need new features and it works for you, don’t update.
The philosophy is still the same: Is it safe to update to a new release of Gig Performer as soon as it is released?