Seems to me the article covers most of the likely reasons.
I would add that relying on traditional channels (agents and NYC publishing houses) puts them in direct competition with native-source content that doesn't require translation and is thus cheaper and doesn't risk losing the flavor of the original. Moving forward, they shouldn't expect much change: with non-bestseller advances inching lower, tradpub investment in new content isn't going to have much room for added up-front investment that may or not correctly capture the magic of the original.
Amusingly, the french's designated villain du jour is one of the few tradpub channels actively looking for mass market foreign works to bring to the anglosphere: Amazon Crossing.
http://phx.corporate-ir.net/phoenix....cle&ID=1428575
Given the explosion of quality native-english content (backlist and indie published) coming to market through the ebook disruption (and to a lesser extent POD) they shouldn't expect to find much appetite for translated mass market titles until one such hits a 50 Shades-style jackpot. And even then, they might be shocked by the prevailing contract terms offered by the corporate publishers.
They might be well advised to take matters into their own hands and do their own global english release via ebook and POD.