I'm a little surprised at the original asker's question, and his suggestion that the UK may be culturally behind on this aspect because what you say is true, of the US.
I've had 5 dev jobs at different employers and all of them have allowed home working. To address your points relative to the UK:
(1) I don't think this is true in the UK, developer salaries are still very much on the increase and have been for years. Companies are still stuck having to improve terms and salaries to get the necessary staff. If you can't go to market and receive job offers from at least 3 different employers with reasonable salary and benefits packages in the UK in the space of a couple of weeks as a software developer then you're doing something very wrong.
(2) I've never even heard of stacked ranking being used in the UK. I'm not entirely convinced that some elements of the way it's done in the US and used to determine redundancies would even be legal here.
(3) I don't think outsourcing in software is as prevalent here as it is in the US, I've worked at employers that used it but it's always been used in addition to, not instead of home grown talent. Experiments in outsourcing to India at places I've worked have always been failures, it's a classic case of you get what you pay for and the quality of developers being put forward by Indian outsourcing companies is beyond a joke - it costs you more to pay people locally to fix their code or even rewrite it than if you'd just hired a wholly local team in the first place. We do have offices in Eastern Europe with large teams of developers, but these teams are managed by the developers back here.
(4) Again, I don't think that's really the case here. I've seen companies that try and emulate that Silicon Valley trend but it's usually the small companies that don't know any better having dreamy ideas of being Google telling themselves that if they just do what Google do it'll all be great, but it never works like that because they don't have Google's budget to pay insane salaries so rapidly realise they need other sweeteners instead.
But beyond that there are other reasons why working from home shouldn't be a problem in the UK, not least because in the latter half of last year the UK government enforced a legal obligation on all employers to properly consider requests for flexible and home working:
This change in law means that unless there's a good reason to deny your request, it should be allowed. That means employers have to either start rationalising and sensibly justifying their reasons for denial, or they must simply allow it. Simply saying "No because that's different to what we've done before and we don't like change" isn't a valid response.
Personally I've tried home working in a number of different ways across various companies. At some employers it's typically been one or two fixed days every week, only adjusting if necessary to turn up for meetings. At others I've typically just homeworked during crunch time - the employer needs a 7 day week out of me for a couple of weeks running, and in return I get to do that 7 day week from home and get to bank the extra hours I do as leave. I didn't mind this, I did 22 days straight but then got all my weekend days (and a bank holiday back) so was able to use them to have a whole week and a bit off a week later post-delivery.
But I typically like to do it around certain tasks, if we're in the product concept and design phase where there's a lot of back and forth, and a lot of discussions over ideas and a lot of decision making then I come into the office. If I'm doing a rather solitary task like just churning through a bug fix list, putting together a detailed design doc once all the decisions are made, or trying to find a solution to a complex problem without any outside support then I much prefer doing that from home where I can focus on the task at hand with no interruptions, and with the benefit of an extra hour in bed of rest due to not having to commute. My current employer lets me work from home one day a week, and if there's reason to do more, I just let the director know and it's done. They usually get more hours out of me, I usually go halves on the commute- so whilst I typically take back the time on the morning to have a lie in or get something done, I usually use what would've been the commute home to put extra effort in - they get an extra 45 minutes, I get an extra 45 minutes and the train company and road network has one less person to try and cram in for a day.
There are plenty of jobs in the UK that don't do homeworking, but it shouldn't be hard to find those that do, and those that do will only become more prevalent with the government's latest push to let people work flexibly. It's frankly win-win for everyone - it means less pressure on commuter trains/roads/buses, it means less of an environmental burden from commuter pollution, it means employees are happier, it means employers don't necessarily need as much office space, and it can mean more productivity too if done sensibly. It benefits the government and hence the tax payer, it can benefit the employee, and it can benefit the employer. Another reason the government is pushing it is because if it means people can get from their house to pick their kids up sooner than they could from a place of work that it means there's less need to subsidise child care too - there are a lot of ways in which it can help wider society.
Yes there are people that take the piss, but frankly, if they're taking the piss at home you can be rest assured that when you think they're in the office working they're actually just browsing the internet, tossing it off chatting around the water cooler, or pissing off to hide in the toilets, to "grab a coffee" or "go for a smoke break" every 5 minutes anyway. Unproductive staff are unproductive staff- the solution to that one is to figure out why they're unproductive.
I understand some people just don't like it and can't adapt to it, and that's pretty understandable. Part the reason it works for me is because I did full time post-graduate studies whilst also working a full time job, the studies were nearly all done at home, so to get everything done in my life I had to learn to be disciplined at home.
Your views match precisely with what I've heard about the culture in places like Silicon Valley, but we have a completely different culture here in most of the UK in my experience.