It is true, but migrating a forum of this size to another platform is not an easy task. On the other hand, I have seen many forums "die", as they migrated to other platforms and were unable to guarantee all the features that the community is used to on the new platform.
This was probably due to there being
better alternatives to the forum, rather than the new platform scaring people away. Unfortunately, humans in general hate change, and therefore any big or small change is usually off putting, but given enough time we'll adapt to anything put in front of us. So. although at first it might seem significant that it doesn't have x feature, or you don't like the design elements, it quickly evaporates away as you become more familiar with the software.
