I wanted to respond more to some of this yesterday, but didn't really have the time. Paulus, sorry for cluttering up your thread!
The thing with voting patterns is that the players are smart enough to realize that 1) they can be manipulated and 2) the bad guys know this and will go out of their way to erase any connection to each other.
Yes, of course. Which in practice only means that you look also at other things to determine if a vote is suspicious. Was a convincing reason given for it, or was the person just making an excuse for having to keep off the same bandwagon as his buddies? Does the person have a pattern of only hopping on already-developed bandwagons? What about consistently being the third or fourth vote on bandwagons that end up lynching innocent players -- the votes that turn it from a random thing into a real threat? What if someone who later turns up a wolf also had a couple of votes at that point?
When the bad guys learn to avoid the really obvious traps, you just set other ones for them.

But all of this is a lost cause if people don't generally vote, and/or don't generally give reasons for doing so.
Now a days, voting patterns are no longer as useful not because no one votes but because of how the games are constructed.
Early on (before my time) voting patterns were the main evidence for the innocents. Hell, I think I recall seeing somewhere that in one of the first games all of the wolves supported each other and when one got caught the rest had a date with the gallows soon afterward. After that game, the players learned to split things up and not appear voting in a block. Eventually the bad guys would figure out how to use the voting to their advantage.
Look at Catharsis' NOTW XVI (well, maybe you can't, but I'll go on). Pinman and I used the voting patterns to not only prevent a connection to us being made but also to use our night kills to frame other innocents. I'd look at the patterns, decide who was frame worthy, kill someone that night then have Pinman during the day talk up a storm to get our lynch target killed. We did that for pretty much the entire game and we ended up winning without losing a single wolf. I'm fairly certain there wasn't any prophet in the game or we had axed him early on. In any event, the voting doomed the innocents.
I think you blame the wrong thing. Excellent play by you and Pinman (and offing the prophet) doomed the innocents. You can't use an example of successful manipulation by the game's foremost manipulator as reason to discredit the data upon which the manipulation was founded. That's just what Pinman does, and he'll use whatever tools are at hand. If there are none, he'll just make stuff up.
But I think that's part of the game, too, or it should be. What I want is everybody questioning everybody else, actively so. Pinman, for example, is not stupid. When he gets the vote data wrong several times in a row, it's time to lynch the scumbucket, no matter what he's saying.
As games got more complicated, voting patterns as concrete evidence went the way of the dodo. The advent of multiple bad guy sides really has screwed voting. Before, it was rare bad guys would accuse bad guys as (duh) they were on the same team. Not anymore though. In your game Renata, because the two War Party sides kept on accusing each other until they teamed up, I was unable to use the patterns to deduce who was bad and who wasn't. With bad guys accusing seemingly other bad guys from day one, the incorrect connection was made that they were all innocent. Not to mention the prophet self-destruction which doomed the innocents as well, but coupling the two together makes it seem pretty obvious how/why the bad guys won so decisively in that game.
That game, just about everything that could go bad for the innocents did. No lucky hit by a prophet, no wolf-on-wolf death, oyzar's misinterpretation of his PM as regards ZPV; no lucky bandwagon (J-man) until Day Six or so; I could go on and on. Lack of voting evidence is the least of it.
But I do take your point. Multiple wolf teams makes things much harder. (Conversion mechanisms make it almost impossible, which is one thing I don't like about them.) But even then it doesn't mean that votes are not useful. As an example from the opposite side of things: in Chandrasekhar's game I had Ekolite and Nictel as almost certain innocents in large part because of their voting (which filled in the gaps in the prophet records we had) -- nobody wanted to trust my conclusions! (Ekolite didn't help by lying like a rug.) But I was right. And in any case there are things that wolves/mafia tend to do with their votes that are different from what innocents do, even when the votes are spread around nicely or there are multiple wolf teams; I named some of them above. Nobody here is especially practiced in looking for these things, but that doesn't mean they don't exist.
The point I'm making is the games have evolved so much that voting isn't be the main evidence anymore simply because the games have gotten so complicated. If the games were simple, as in one bad guy side, one innocent side, and maybe a prophet or two, then yes, I can understand voting as prime evidence to use. But now with bad guys with conflicting vc's, it's damn near impossible to differentiate anything anymore.
It's only part of the picture, but I think it's an important part, and not just because of its usefulness for innocents (or even wolves). It also adds a lot to the game. It's something anyone can do, whether they've been prophet-scanned or not. It adds conflict and interest to the public thread. And it's fun, in itself. For me, anyway. Take away any requirement or pressure for people to make reasoned votes, and all that tends to evaporate.
(And all that said, before we gave up entirely, I was contemplating trying to convince Ekolite to go with just one real bad-guy group (maybe some non-exclusive third parties for interest) for our game, as a bit more reason to bring vote records back into the game.)