Anyway, let's stick to the topic. Building a portfolio just require 1 - 2 jobs, but a solid portfolio with your own style takes years. But I do agree with some of suggestions to learn under another established photographer, for one, you have someone there to guide you and you get to pick up some techiques along the way; not to mention, there's less risk of messing up, it's not your job anyway, esp for wedding, you have to be very careful what you're treading on...last thing we want is another incident of bride going around forums to rant about how bad her $250 photography is.
It's not a matter of oh-I'm-paid-low-therefore-I-can-mess-it-up-and-what-can-you-do, whether you're paid $10 or $10000 for a job, you're a paid professional who have agreed to do deliver something.
In context of wedding photography, I do notice that the new breed of photographers who tagged with the pros have been given better exposure and opportunities, for example, you get to chance to shoot at St Regis hotel; they get to travel overseas sometimes to some of the locations with golden hour that lasts 6 hours, grand setting, great lighting, nice looking wedding favours, nice posh hotel rooms, Rolls Royce, Vera Wang gowns, etc, etc. Yes, at the end of the day the skills matter, but the locations will give you an edge.