Why does the article take issue with Mozilla alone? Surely they aren't the only browser vendor that won't be implementing native client. Mozilla is being singled out here precisely because other major platforms are considered to be lost causes.
Safari and Internet Explorer are unlikely to support NaCl for obvious competitive issues. Heavily curated platforms like the iPhone prevent even third parties from supporting such a feature.
Once you realize that even with Mozilla support you'd still only be looking at a ~60% penetration, you're going to be working around it anyway. Once you're dictating platforms, plugins or providing a fall back implementation I'm not sure if support in one specific browser is going to make or break anything. If you're willing to target only half the web you're simply not that concerned about ubiquity to start with.