Let's be clear that the article posted by the OP referred to "on-street bi-directional cycle tracks" as opposed to "physically-separated, next-to-the-street, bi-directional cycle tracks". Let's also be clear that the article's author specifically defined the track's separation from car travel lanes as a painted line.
When some "segregationists" talk about segregated infrastructure, they are referring to a track with a physical barrier separating bikes from cars. One group, for example People for Bikes, uses the term "protected bike lanes".
What bothers me with so many of these polarized discussions is the lack of useful data. Frankly, I don't care what Copenhagenize has to say. If we genuinely care about safety, we should genuinely care about data and not all this huffing and puffing. I'm currently working with my town to design a key roadway and it has not been easy to make strong, data-based arguments for any given design.
Due to certain physical constraints, we probably do not have sufficient room for uni-directional, off-road cycle tracks. We are left with less-than-optimal choices. We will definitely be providing either four-foot or five-foot uni-directional on-road bike lanes. We are looking into the possibility of also providing an off-road, i.e. physically-separated, uni- or bi-directional cycle track or perhaps a multi-use path (i.e. a very wide sidewalk that would be shared with pedestrians, bikes, etc) parallel to the road.
The question we have is whether an off-road cycling facility is safer than an on-road bike lane? And, if it is, would that be true regardless of whether it's a one-way or a two-way facility? The road in question has very few (and minor) intersections although there are numerous curb cuts (businesses and residences).
I must say, and I'm a long-time VC cyclist, I get really turned off by what I see as elitism from some of the hard-core VC folks. The goal is not to build safe cycling infrastructure for very experienced cyclists; the goal is to build safe cycling infrastructure for all cyclists. I always wonder whether those who argue for no separation think weak, inexperienced cyclists should just stay home or just ride around in circles in the schoolyard parking lots on the weekend. On the other hand, if separated facilities are not safe, then even the goal of appealing to inexperienced cyclists does not justify them. From what little data I've found, well-designed, segregated facilities clearly will result in increased usage and they can be relatively safe.
Cycling advocates, it seems to me, should have two objectives: safer facilities for all bike riders and increasing the number of people who ride bikes. I don't think VC ideas fulfill the second objective and it's not clear they fulfill the first.
For what it's worth, here are a few links I've been reading that discuss some of these issues:
Two-way cycle tracks are fine, just look to Montreal | I Bike Toronto
Protected Bike Lanes 101 | PeopleForBikes
Q&A: New League study challenges assumptions about fatal bike crashes | Bicycle Retailer and Industry News
I run a bike club in my area and I can't tell you how many times I've heard the phrase "I would never ride on the roads." Whatever design we choose to endorse should provide a useful response to these people. We see very few kids riding anymore. Something is clearly wrong.