I think what you're noticing is that Attitude is out of stock on all of Barney's regular seeds.
http://www.cannabis-seeds-bank.co.uk/barneys-farm-regular-seeds/cat_25.html
On the other hand, Attitude seems to be almost fully stocked on their feminized seed offerings:
http://www.cannabis-seeds-bank.co.uk/barneys-farm-feminized-seeds/cat_62.html
For whatever reason Barney's seems to have made the decision to offer only feminized seeds. Other seed banks, like Greenhouse, also seem to be moving in that direction. IMHO that's not a good trend.
Putting aside the fem vs regular seed debate (because I think there are arguments to be given that justify the use of either based on a person's unique situation) one possible motivation for a seed vendor to move to fem seeds is that it protects their "proprietary" genetics a little bit more than regular seeds, well, at least that's a theory of mine ...