Very odd that Virgin thought messaging was a good feature to add to their 'entertainment' system. I'd have thought its usefulness would be very limited. But no, on reflection, it's the usual techie thing: we can do this neat thing, so let's add it to the system.
If I'd implemented this feature I'd have disabled it by default, when the system is reset before each flight (I presume it is?), and let each seat choose whether to enable it or not for that flight. Then I'd have let each seat choose whch other seats to take messaqes from. Allowing messaging from random seat to random other seat is asking for silly behaviour by teenage dickheads.