Maybe that's your personal experience but that is not everyone's experience. I get links from large corporate websites from the likes of Hearst Publishing for my high quality site- simply by asking and most often without asking.
find it ammusing when folk expect linking to just take-off, go auto-pilot, critical mass
I do not doubt your personal experience of links has given you this view. But it is not true for everyone. Different kinds of sites have different linking patterns. In other words, what is true for you is not a universal experience. Your personal experience is not Universal. Because it is raining over your house does not mean it is raining around the world. So perhaps you need to reword the way you phrase things so as not to appear to be representing your personal experience as those of the entire Internet? ;)
Self-reinforcing inbound links is a commonplace for large and popular websites. It's not easy to get to this point. But that particular experience does exist. It's a real phenomenom. A link echo-chamber effect is real. High ranking across a range of phrases tends to be self-reinforcing. People find you on the SERPs and link to you from their news articles, their corporate website, from their blogs, from forum posts.
I monitor my referrals and see it every day. It happens. It's why some sites sit their fat asses on the first position and can't be moved. Being number one tends to reinforce their rankings as long as searchers find the information useful.