It appears the second article linked is a decade-old opinion piece talking about a series of skybridges as a means of transport throughout a city. It does not address the obvious use of them, connecting a hotel to the convention center it serves, allowing catering services to cross safely. As already demonstrated in this thread (or the hotel thread, they both overlap), any use for people is secondary and does not, in fact, prevent people from using street access. I haven't seen anyone (until just a few posts ago) suggest (from the article): "Elevated walkways as an urban design (or even suburban design) element".