What I think, as a person who would be GMing the game as a Forever GM and explaining the system to players who probably aren't going to buy their own copies of the rules...Like, in the case of three different perception skills, does it lead to better spotlight sharing in the information gathering department, or does it just mean scout characters have to buy multiple skills to do their job? How does that compare to other specialists and the number of skills they need?
How do I explain the difference of these three skills? How do I quell arguments when a player doesn't get to use their highest scores? How do I explain "in the world" something illogical (Sam with a High Strength)? How do I explain to a player that their fighter who is maxxed out in Strength is now the party's face?
How do I remember these rules when they're seemingly assembled randomly? I probably have 2-3 other systems rattling around in my brain - and especially if the rules aren't logical, I'm going to mix up things.
How do I make a case to play "this" game (opposed to others?) If we're already playing a game that we understand, what's the value of learning something that doesn't really add anything? If it's not very clear how I will answer that, it's probably a losing enterprise.