I would instead say that PCs are boring because - unless you specifically install development software - they can only do what other people have set them up to do. This is triply true if the PC happens to be running Windows.
The old 8-bit micros were the polar opposite. Unless you went out of your way to obtain pre-made software, they could only do what you told them to do. You therefore got a much more visceral thrill when you achieved something with them.
I would say that's true in the same way that a prodution line car is boring against a kit car where there's the excitement of getting it to work yourself.
You're absolutely right; if development software isn't installed you cannot do much though I'm not sure why this is "triply true" for Windows.
I think Chromatix has a very good point here. I'm not saying we all didn't thoroughly enjoy a few rounds of Invaders sometimes (fine, most of the time...), but I think the people buying micros were mainly doing it because they were interested in programming them (and were/became able to do so), not so much because they wanted a game console. These days it's quite the other way around, most people buy computers to be used as an appliance and most never manage to get them to do anything they'd like them to do even if they might have such an interest (yes, some do; many never manage and just give up).
Perhaps programming was more fad of its times, like the flood of garish 72-point font web page with a 'this is my kat tiddles' picture against a flashing yellow and pink background when 'the web' became mainstream. People simply evolved, found the tools they want, and moved on with what they want to do rather than having to build it all for themselves; most people are happy they can buy a car, not have to build it from a kit, can use Wordpress et al rather than have to write their own blogging and forum software.
Personally, I think we live in a particularly unfortunate period right now in this regard - getting a micro do what you want was not that much of a problem back then, and I firmly believe some time (hopefully soonish) we well see the emergence of tools that will allow anybody who can articulate what they wish their machine to do to actually achieve that without much/any overhead. Right now we definitely don't have that ability though; knowledge of arcane IT intricacies is orders of magnitude more important to actually achieve a goal than being able to see the way to achieve it - and I think that's a real damn shame.
Relative to your analogy - yes, people of yore are kinda similar to automobilistic pioneers who were happy to tinker around their machines as opposed to modern users of. But I also think contemporary software is rather like public transport - you can only get around between predefined stations using it, not were you'd like to go. And given the choice between that and your own car you can use to go exactly where you wish, I think we all know which one people tend to prefer.
There are always those who want something different, want to do it themselves, but there has been little holding them back from that. I would guess people, like me, have been knocking-out code on whatever platform they choose for years for their own and others' enjoyment. It's not that PC's are boring, but more that people are; in the sense they have no inclination to program or to learn how to or perhaps there is not enough help for those who wish to but cannot.
Let's just say I have at least one example of "those who wish but cannot" - There is literally no MCU I have met that I could not bend to my will (given appropriate level of documentation) with remarkable performance and reliability (once I find the odd bug or two), yet I have pretty much failed to do any meaningful programming on PCs every single time I tried in any single language - and I have tried lots of times; I manage to meddle just enough to realize I'm no good with them whatsoever. Sorry. Maybe I just have the dumb and cannot brain. Needless to say how much fun that makes reporting bugs for any software and getting the standard "fix it yourself or STFU" answer.
Programming as a hobby, for fun, entertainment and self-reward, is what's really diminished, much like other hobbies of metalworking, woodworking, ham radio and the like. I hope the R-Pi kick starts the hobby again, even leads to future education and careers in computing, but I don't think it's fair to say PC's have held back those who have wanted that.
That is possible, but I can't shake that "the train has left the station" feeling - actually, the minimum standards departed to some nearly unattainable heights. Yes, some people happily code away at (indie) games that make my jaw drop. A bunch of others, however, are left with the choice of creating grossly sub-par stuff or admitting they are unable to hit a decent standard. When "Invaders" was cool I could create and animate 8-bit pixel sprites as well as they could, but today that will get you nowhere both art- and coding-wise. Just look around the websites of a bunch of "easy-to-use beginner languages", in the "sample apps" section and you'll know what I'm talking about; the general (and quite often the top!) level of the stuff you'll usually find is enough to make one cry... Yes, I know it has been mentioned that technology is not the most important part of making something really good, imagination is. And incidentally I mostly agree. But only mostly: if imagination is enough, why aren't we all playing / creating text-based interactive fiction or games like Nethack instead of the likes of Mass Effect...? </rant off. sorry...>