You've definitely gone from one extreme to the other there - from a steel-forked, low-end Halfords bike, to a high-end bike. There's a whole load of stuff in between which offers a great balance of performance vs cost and whether you are a sport rider, or a commute rider you need to pick the one that suits you. I can only speak for myself when I say that I'd rather risk a decent bike being stolen from outside the cafe than do a 100 mile ride on a low-end bike! Yes, there is a law of diminishing returns and the difference between a £5,000 bike and a £10,000 bike may well be hard for a casual rider to spot (and even harder to justify!), but pretty much any cyclist will be able to appreciate the difference between a £300 Halfords bike and the Scott in this deal and I would say that few would choose to go back after having ridden the better bike. Anyway, each to their own and all that.
I didn't say not to have a more expensive bike I said for everyday use where it could get abused and stolen it could be overkill and less than ideal. There are a lot of entry level Claris road bikes that have aluminium frames and steel forks like the Carrera Virtuoso. They are about £300 thereabouts. In your situation you have more control either end of your journey but that may not be the same for everyone. Some people may need to store their bike outside in a less secure area both at home and at work and may stop off at other locations where the bike isn't securely stored, shops etc. It's really down to your area I guess and how chilled you are about your bike being stolen or damaged. Some people think positively until sh*t happens others think about sh*t happening before the event especially in a high crime area. I've seen forum postings where people have bought high end bikes for normal use and then seem to be constantly worried about them. I was looking at 2 Brompton bicycles outside a pub and I could see someone looking out the window clearly in panic mode thinking I was going to steal or maybe scratch up the bikes who was clearly one of the owners of those bikes. I just feel that for most people the tiny performance gains of a high end bike can be offset by many negatives to owning such a bike be it more easily damaged, more likely stolen and higher maintenance costs requiring higher cost replacement parts.
OK, your point about nailing a posh bike to some railings is fair, but implying that you shouldn't even own a half-decent bike is a bit over the top, tbh. After all, my takeaway from that video was "bike securely locked to bike rack successfully foils potential thief. Viewers mostly disappointed that noone chose to run him over too." If you have nice kit, you need to look after it, but I'm afraid that saying there are bad people out there, so I won't own a bike worth more than £300 is both unrealistic and, honestly, a bit defeatist. There are plenty of people who commute between home and office and have secure storage at both ends (mine literally sits by my desk!) and similarly, plenty that choose to use carbon bikes for such activities too. It's also worth noting that you'd really struggle to find any bikes in the mid-range (way cheaper than list price on this one) that don't have at least a carbon fork, because of the material's natural dampening effect on road noise and general reduction in the cost of such components on a frameset. Many cheaper bikes might pair one with an alloy steerer, but above £1000 I'd expect full carbon forks on most road bikes. Sure, there are still bikes available with full steel, aluminium or titanium builds, but they are becoming more niche and you'll pay heavily for the privilege of owning one. For me, at least, I now only own carbon bikes, having gradually whittled away the alloy ones over the years and value the ride dynamic and light weight of them. I'm yet to have one break on me...at least not without incurring a fair amount of blame myself :-)
All good points but aluminium frames always get weaker with time and often ride more harshly. Where as carbon frames often have far better ride quality but are more vulnerable to damage. The other point is the most dangerous carbon fibre component is the forks which are often fitted to aluminium framed bikes too. That is the component most likely to fail without warning and the most dangerous. Failures of carbon fibre frames are less likely to be as dangerous. That info is from Luescher Technik on youtube who is a big carbon fibre fan and expert repairer of carbon fibre frames. From a safety viewpoint it is better to have a carbon fibre frame with steel forks than an aluminium frame and carbon fibre forks, not that anyone configures a bike that way with a carbon fibre frame. Personally I wouldn't get a carbon fibre bike as an everyday commuting, shopping type bike I'd stick to an aluminium or steel frame with steel forks and would only consider carbon fibre as a weekend leisure riding or competitive racing type bike. I saw a carbon fibre bike locked with other bikes in a rack and the 2 older road bikes had fallen over onto the carbon fibre bike and could have caused damage, I didn't stop to look in detail. Not really robust bikes that can take much abuse with everyday riding and I prefer bikes that take more abuse and are less appealing to thieves. I always find it re-assuring in the past if I lock my bike up in a rack that has a higher end bike also locked up as that bike is far more likely to get stolen. Here is a thief who has decided he would rather have this nice carbon fibre bike rather than the lower end bike he currently has. I guess my point is not having to worry about theft so much is for me an appealing part of having a lower end bike. https://www.youtube.com/watch?v=CBn_HCTZiYc
I think it is because you're not looking at a cheap 800 quid carbon bike, it's a 1600 quid carbon bike.