This has been a valid argument.
Today, it does only apply in part - but could still have 'disasterous' results.
Back then, you could not know, how many more core modules would be released - or how many decades it would take for that matter. This made it impossible to come up with the 'perfect storage' up front.
Today, though, WW2 is (almost) entirely covered in terms of ASL counters (by MMP). So, if you start building your storage system today, you can use an existing plan that addresses (almost) everything - even if some of the core modules are currently out of print. In other words, you can do things 'right' from the start, since there won't be (almost) no new counters for 1939-1945, making the situation stable and plannable.
The (inevitable) EXCs are minor additions such as the Eritreans and Ethiopians now added in the most current version of 'Hollow Legions' that were not part of the previous version of the core module. If you don't have any 'spare room' in your existing storage system, this can really screw things up.
That said, things like the Korean War or the (upcoming) Spanish War core modules serve less of a problem - at least from my perspective. As they are not part of WW2, I keep them entirely separate from the other counters and thus they do not pose a 'grave danger' to my existing storage system.
Personally, I try to avoid using TPP counters if at all possible - no matter how well made or colorful they might be, I find extra counters not covered by MMP or alternate counters to those of MMP more a burden than a boon. This is also due to my preference of the 'classic' black/[nationality color] combination over any multicolored variants. If you take TPP counters into the equation, then any 'perfect storage' is not going to last, as there are too many of them, too many new ones, or too specific (like unit specific counters). Of course, each to his own - its a matter of taste, I acknowledge that.
von Marwitz