I understand your theory, but I dont' understand what you mean with "the subSilver2 style is not working with phpBB3" - (in an aesthetical sense).
It is a bit much to compare the three projects so directly. phpBB1 was of course the beginning and it did not have the same life cycle as phpBB2 enjoys (remember phpBB2 is the leading project in a sense). It is the longest serving application and the most used. So, after phpBB1 when phpBB2 came along there was lots and lots of changes of course and it had a brand new style that shipped with it giving it that instant recognition. phpBB2 is of course at this moment still active and there is a likely chance that a lot of people are still using it, we cannot be certain about the amount of boards that have not yet made the transition to phpBB3 yet.
When the development of phpBB3 began (years ago), the "subSilver" style was used initially to aid the development (it gave the development team something to use visually), because "subSilver" was the leading style it was ported over to phpBB3 - and thus it was named "subSilver2". As time went on, the development of "proSilver" started, we wanted phpBB3 to be something special and of course this meant it needed to have a brand new style to go with it, something cutting edge and dramatic.
Now, as with the transition of phpBB1 - phpBB2 the same has happened again with phpBB2 - phpBB3, but for the styling side there were a lot of major changes, especially to the layout markup. These changes almost reflect the changes in the industry, as the move away from highly using tables is now much more prominent. We know a lot of people who used phpBB2 were much more familiar and comfortable with modifying the layout with tables etc than what they are compared to phpBB3 which is more inline with todays standards. In this aspect I am referring to the people that have used phpBB2 for a number of years and not necessarily people that have came in at a time when phpBB3 has already been released.
greenweaver wrote:we cannot be certain about the amount of boards that have not yet made the transition to phpBB3 yet
So to go back to the above, the main reason why "subSilver2" exists is simply because for those in the community that have used phpBB2 and subSilver for so long we wanted them to feel comfortable in their transition over to phpBB3 - hence we added two styles to the release. The "subSilver2" style for those that enjoy that style and of course "proSilver" for those looking for something a bit different. Please remember also that a lot of people enjoy the "subSilver" style and I am sure they would be disappointed to see it go.
Besides, "subSilver" is such a novelty and iconice style - why not keep it? Perhaps you will see it return once again when we announce the release of phpBB4