I think you're missing the key point of RangerWickett's insightful post. The level of restriction is not as damning as you make it out to sound. Because of how easy multiclassing was in 3E (and in some thematic ways, way too easy in my own opinion), the interlinking of paths was more vivid/profuse than in 4E's rather rigidly set class options.
I'm not talking about how easy it is to mix classes. That's irrelevant unless you're only worried about mixing themes.
It may be easy to mix and match levels in 3e, but its insanely difficult to mix and match
class abilities. This is because they're stuck to classes and have ENORMOUS prerequisites. Let me put it this way- if you want to obtain the level 7 ability from the Duelist PRC, you not only have the prerequisite of dodge, mobility, weapon finesse, five ranks in tumble, three ranks in perform, and a +6 base attack bonus, you also have the prerequisite of
six entire levels of the duelist prc, all of which contain class abilities you may or may not want! That's HUGE! And that's not even addressing issues of whether more carefully mixing and matching class levels can let you meet that enormous prerequisite earlier in your career (instead of going straight rogue to level 8, you could go fighter to level 7, or else you could go fighter 4, rogue 3, swashbuckler 6... etc). And if you wanted to obtain that level 7 duelist ability and combine it with a particular ability from another class, heaven help you unless that other class ability is available at a very low level.
I do not consider this free form. This is intricately mechanical and hardcoded. The whole system is filled with IF you want this, THEN you must do that. That's not free form at all.
I had FUN with it, don't get me wrong, but I knew darn well that I wasn't doing free form character creation.