Quite amusing how people get so tetchy about what bike is suitable for commuting.
If you're going to spend up to £1k to be honest you're splitting hairs about the intracicies of a particular groupset or brake type. Broadly the order of important points should be:
- terrain. Road = anything, but better with skinnier tyres for less rolling resistance. Off road, then wider tyres needed generally.
- distance of the commute and whether bike will be used in all weathers. Mudguards or no mudguards
- stuff needed to take to/from commute. Panniers, backpack or saddlebag/barbag.
That's about it really, everything else is second order.