If the "bar" of their proprietary capturing engine is set lower than NAM, they can only set it higher by supporting it.
If it is set higher there's nothing to lose for them cuz users will prefer the better solution anyway.
So I really don't see the issue.
NAM support doesn't stop the race for improvement, actually if it's a feature that will help them sell more units, it's something that can fund and push further that race. NAM isn't perfect either.
Improvement isn't only about quality anyway, also having an industry standard is an improvement for usability.
Just imagine all modelers only supporting proprietary cab formats and not allowing to import wav IRs: people that play with more than one platform would be forced to search, buy and use different IRs for each of them, or 3rd party producers would need to do double/quadruple work to offer their IRs for more than one platform.
Having a universal format for IRs didn't stop companies from introducing dyna-cabs and similar, for example, or to sell their own cab packs in proprietary formats.
Being able to load your tone on the hardware of your choice is a huge improvement imho and I bet this will expand to effects in the near future as well. Companies can still add value to their hardware by making their platform-specific content which can still be higher-quality or have more features than a capture.
