I'd really suggest that if you don't want to vote for Brian May that you not do it. Especially if spending the one vote allowed per day on this day only in the Guitar World poll keeps you from voting for or requesting Trespassing.
Your two biggest objections to Adam's fans choosing to support Brian in this poll seem to be that it is meaningless, and that it has nothing to do with Adam.
Allow me to disagree. As far as meaningless efforts go, Guitar World Magazine is a respected and credible publication for serious musicians and the music industry, more like Rolling Stone or Billboard than like, say, People Magazine would be. Ranking well in this magazine merely adds to the prestige Brian already experiences by being ranked #26 greatest guitarist of all time by Rolling Stone. It will be mentioned whenever articles are written about Brian, appended to his credentials much like (unfortunately) "runner up on american idol" may always be mentioned in articles about Adam.
As far as what, if anything, this has to do with Adam, perhaps there are other musical legends who have given Adam an international stage to perform in front of many millions of people at something like the EMAs. Or the opportunity to perform before 350,000 people in Kiev, or sold-out arenas in Moscow and Poland, and I've just forgotten them. I daresay, had the Olympic Committee not insisted on British citizenship for their summer olympics, according to Roger Taylor we would have seen Adam singing at the Olympic stadium too.
Personally, I believe (and hope) that there will be future performances for Queen + Adam Lambert. If so, they won't be at casinos or county fairs. They will be in Madison Square Garden, or maybe the Hollywood Bowl. Someday. Certainly it seems that Queen is not through performing and have no wish to retire. If and when the right opportunities present themselves to Brian and Roger, Adam will be their vocalist of choice.
As far as your comments about how the Queen fans don't support the band members in these types of efforts, that's true. It was well established during our Queenbert phase that much of the Queen online fan community believe that Roger and Brian should have just retired when Freddie Mercury died. Apparently Roger and Brian disagree, and thank the gods for that! Brian and Roger have given Adam some unbelievably spectacular opportunities. Their own "fans" may not support that, but I don't think it hurts a bit for Brian and Roger to have the distinct impression that Adam Lambert's fans are appreciative of those opportunities, and are always gracious and supportive of those who have helped Adam to the extent that they have.
I enjoy participating in that gratitude. Some of the other fans seemed to enjoy it today too. I don't think it kept anyone from voting for PopCrush +20 spins, requesting Trespassing, or playing whackamole.