The additional wire and type of wire should NOT be passed over, there are many measurements to indicate the issues there. Dampening factor losses, power losses, capacitance added with length, etc are the simple issues. There are more complex ones as well. There is a long list of differences detailed by so many in cables, how can these differences suddenly not matter when discussing active vs passive?
In addition to the issues of wire and which ones sounds "right" or wrong, there are even more issues/problems:
1) phase: you cannot adjust driver phase in passive. A phase linear speaker system is very important to best possible sound.
2) Changes with heat and temperature of drivers: as drivers heat up, they change properties and interact with a passive crossover in a way that can change the crossover point, the sensitivity, etc. The long and short of this is that the speaker sounds different "hot" (on for 5 hours straight) vs. "cold". Not true in the same way with an active system. Most passives are NOT phase linear because you cannot have precision in adjusting this phase via passive components. With active, its easy.
3)The driver never "sees" the amp: there is a significant amount of stuff audio is traveling through (wires, inductors, coils, connectors, etc) permanently between all the speaker drivers and the amp. How can this be said to actually improve transparency? The obvious answer is it doesn't improve anything. It also makes it difficult if you replace drivers that have ever so slight difference in sensitivity: this is not adjustable unless you reengineer the entire crossover.
4) Adding a bunch additional circuitry seems to be a negative in almost all situations, many electronics companies talk about reducing the circuitry to improve performance. Why here, in this amp to speaker location, is it pitched as BETTER to add bunch of extra parts ?
5) If you are a speaker designer, that doesn't mean you are also an amp designer and vice versa. So most speaker companies must go elsewhere for amp designs, making the entire project more complex and involving more engineers. Few have both disciplines in the same house. (Genelec and ATC were the pioneering companies in active and their founders could do both).