Every time there's a patch, half the people rage out on the forums and swear they're calling their divorce attorney on Rito.
Admittedly, sometimes the rage accurately assesses the situation, but Riot is making changes to champions with every patch, and it's not long before most troubles are fixed (eeeehhh maybe not ALL of them, but many of them). However, it IS a long time before the feelings of hardcore-<insert-champ-name-here>-veterans are no longer hurt. Because let's face it, moba players have long memories and tend to spend more time in the past than in the now.
Related to that: Some patch sequences keep a champ balanced, but DO change a champ's playstyle. The average gamer, being a sucker for nostalgia, crying that all final fantasy games after VII sucked, will have nothing to do with these style changes, and go ring up that attorney.
Then, newer players, looking for expert advice, take it from a bunch of long-time forum goers, acting like a pack of old guys, sitting around a porch, complaining how "it aint like the old days anymore".
In short, if you want advice on a champ, first play them a few games, note the good and the bad traits, then compare your results to what updated build-guides say about the champ. An updated build-guide is a guide from someone who's STILL playing a champ and correcting their play styles to handle reworks. Don't go to the forums, where people post to say they've thrown up their hands and abandoned the game every time Rito makes a tweek.