Perhaps it depends where you are - within the DBMM playing community, the popularity of 6mm (based to 25mm WRG scale convention, i.e. 60mm frontage) is exploding.

There are now large 6mm tournaments, and even 25mm tournaments where 6mm entries on 25mm(60mm) basing outnumbers the actual 25mm when allowed. 

I am in the middle of nowhere... and happy to a point... I still miss the wargames with my brother... he lives too far away and we are getting vintage LOL... I think that 28 mm is getting more and more  Military Modelling stuff... and 6 mm is the true wargamers scale... not much of a blasphemy I guess... but I even indulged wargaming in 75 mm with customized Playmobils!... skirmish of course and no painting at all!. See LOOK INSIDE... no need to buy my book about our experiences... My Toy Soldiers And Me... amazon.co.uk... LOL