A lot of my reasoning follows with Richard Askwith's book, "Running Free", where he feels that "Big Running" (the commercialisation of the running industry) is forcing people to buy into a way of running that is not only financially unsustainable, but apparently can also lead to more injuries! Combined with the amount of money spent on treatments for running related injuries, this looks like something of a vicious downward fiscal cycle. However, he does tangent slightly when it comes to Strava, and other personal health and GPS devices, where his writing becomes a full on rant about the gamification of running, where the reward comes not from the act of running but the use of concepts of video games to incentivise real life. So for example, uploading the data into Strava gives you a target to then beat your old time. While this is essentially the "Parkrun" model (your time is posted online for free and the idea is that you beat it the next time on either the same 5Km course or on a new 5Km course elsewhere), it can be done anywhere, as long as you have satellite coverage. For something like Ithlete, it becomes a little different, since the health monitoring systems aren't deliberately gamifying your run, but the principle is similar; if you follow the various charts and rules imposed by the health monitor, you will be rewarded with (in theory) lower blood pressure, more fitness etc.
I'm not stopping anyone else from using these devices, especially if it is for health reasons, like some of my running partners, or even for the acquisition of PBs in local challenges. But in my position? I don't need to gamify my running regime (in spite of having written a paper on the gamification of archaeology for schoolkids!). I don't need other people following my routes on a virtual dashboard so they can beat my time on exactly the same course. Instead, I prefer to choose routes that offer sights, sounds and smells that you don't get on a road (when possible). Sometimes I'll go out to beat my raging hangover, so I need a nice route to avoid having to concentrate too much on distractions (cars, other people). It does help when you live less than a mile away from open moorland, and of course very few people get that opportunity. However, if you are using these devices as a way of motivating yourself to run then fine, that's your way of doing exercise and that's fair enough. However, if you enjoy running already, but don't want to be setting PB's for whatever reason (usually age), then it creates an artificial layer whereby you aren't necessarily engaging with your immeadiate environment, which I believe is a darned shame. For an analogy, I despair when I see people running with headphones on, especially in rural areas. There's a world of beautiful sound outdoors (even in urban spaces), you're not putting 100% into finding your proper running gait (which may help reduce injury) and you are acoustically blind to potential dangers e.g. passing cars!
My other point against using Strava personally is that in this modern age, all of our data is being used to analyse what we do, where we go and how we do things. This feeds back directly into our online lives- adverts, for example, are now so smart that they will be able to use your data about what websites you've been to, or even what you've talked about on social media, and then be able to target products at you related to those activities. You may not even like these products! But I've noticed a lot of adverts recently that have been rather too close for comfort. For example, I've been looking at applying for the new series of Robot Wars, and having done some research (and nostalgia) by looking at various robot wars related websites and articles, I'm now getting related Wikipedia pages about other things that were part of my 10 year old's life (war gaming, video games, etc.)! This is a part of me that I have, for the most part, left behind but not forgotten. And I'd like to keep it that way. What I'm getting at here is that your Strava (or Ithlete) data could feasibly be used by not just adverts to give you enticing offers on new running shoes and clothing,
... OK, hands up, sometimes I get it wrong. As of the 13th March, 2016, I found this little article on the BBC to do with Strava Insights, which looks like they're giving out their data for free. However, it still proves my point, in that it is still possible. It would just make no business sense to do so anymore! Nonetheless, I don't want to surrender all of my life over to the great panopticon of the internet, just as little as possible so that I can live my real life to the full (this blog post excepted).
To summarise: if you think that you need to use Strava, think hard about whether you are doing it for the right reasons. If it's to motivate you, then I don't have a problem with that, nor with health conditions that require monitoring. But if you enjoyed running in the first place, then I personally wouldn't recommend it. Most of us aren't going to become Olympians, and most of this gear is deliberately designed to get you into that mind-set, which requires a training regime that most people can't afford for time or money. Just go out there and run, enjoy the sights, sounds and smells of your local environment and enjoy yourself!
P.S. If you've been convinced to buy Richard Askwith's book, follow this link!