The entire enterprise of professional sports fandom is illogical, on some level; you're rooting for a group of strangers, most of whom would rather not give you the time of day, because they're wearing a particular uniform. To the extent that any of us might still be rooting for a particular outcome for the rest of the postseason, what it is we're rooting for is largely out of our hands. The heart wants what the heart wants. (My heart was delighted when the Yankees got punted out of the postseason on the first day.)
That said, there absolutely is a "right" team for Indians fans to root for, if an Indians fan's primary baseball interest is seeing the Indians do well. More to the point, there is a "right" team for Indians fans to root against: the Kansas City Royals.
I went to a Big Ten school, and I tend to dislike the other Big Ten schools. My feelings are stronger in regards to some of them than others (Wait, I'm supposed to care about Rutgers now?!), but in general when a Big Ten school I didn't go to is playing in a bowl game, or the NCAA tournament, I'm hoping they lose. I spent all season hating those @#$%, why should I change my mind now? A number of my friends go the other way though; they want other Big Ten schools to win, because they feel it makes the entire conference look good.
While I may hope Michigan gets slaughtered in the Empire Carpet Shag Bowl, in college sports there is a logical reason to pull for your conference mates, because some of the money they collect for their success will come to your school, and if you go to a small school, a conference mate's success can bring a lot more attention to the conference, which might help in recruiting.
Major League Baseball ain't college sports though, and in MLB logic (and the money that drives said logic) dictates that the Royals winning the ALCS again would be bad for the Indians, and the Royals winning the World Series would be even worse.
Like the Indians, the Royals play in a relatively small market, in a state they share with another MLB team. Like the Indians, the Royals have tended to operate with a below-average payroll. As recently as 2013, the Royals had one of the ten smallest payrolls in MLB, lower than the Indians. In 2014 the team decided to "go for it," as it were, and ownership approved a payroll bump to $92 million, This paid off, as Kansas City snuck into the Wild Card Game, pulled off a stunning comeback against Oakland, and made it all the way to Game 7 of the World Series before Madison Bumgarner closed the door on them.
The team's first postseason run in 29 years provided them with a number of additional home dates, home dates at which the stadium was packed with fans who paid higher than normal prices, many of whom also bought a number of souvenirs. The Royals used that extra revenue (and the knowledge that attendance and merchandizing numbers would be even higher this year) to boost their payroll to $113 million by Opening Day of this year, and to $125 million by the end of the season.
The more success they have, the more revenue they'll have, and the better positioned they'll be to keep their core together, add to it as needed, and continue to play winning baseball. It's a shame the Astros didn't have Francisco Lindor at shortstop in the 8th inning of Game 4 of the ALDS, because if they had, Kansas City's season would be over. Instead, they get to sell tickets to at least a couple more games, sell beer, hot dogs, and sweatshirts with "ALCS" on them to the fans who buy those tickets, and bring in millions and millions of additional dollars with which to try and keep themselves better than the Indians.
The Royals' success is objectively bad for the Tribe, and Tribe fans should hope the Royals' success doesn't extend any further.