As someone who has run and played OSE, follows it on various social media channels, doesn't dislike the system, etc., I think the greatest enemy to OSE is the confusing wide range of essentially the same product. New players are frequently befuddled by what to get.
The most frequently asked questions I see online are:
"What do I need to get started?"
"Do I need the Core Rulebook only?"
"Do I need the Advanced Guide?"
"Do I need these two separate Core Rulebooks?"
"What about this boxed set?"
This is the last thing that brand needs.