I didn't do the initial foundational research for the project I worked on, but now that you mention it, I think that was discussed. I think the main issue was that Java really does run everywhere, except iOS, which is unfortunately the most popular mobile device choice. In an enterprise environment that can dictate what devices get used in the field, it's not a problem, just force Android or even Windows on a tablet. In a bring-your-own-device environment, iOS support is a must-have.
On the other hand, bring-you-own-device is a risky business move anyway because App Store rejection is a very real concern. It was a problem more than once for that project.