Yeah, same thing happens to me. Picking defuse mission might as well be the same as picking Dust II. But hey, at least it's not Dust-- I really hate that map because there is not a single point where Ts get sight of the CTs first. Anyway, it'd be great if they could actually make the hostage maps playable again. Starting a few updates ago, Office just vanished from the competitive map rotation so it was Italy all the time. Now hostage mission is a 20+ minute wait.
I think I'm in the minority who likes hostage missions more than defuse. I feel like there's a lot more variety in how things can play out. For example on Italy I was on CT side and the Ts were all camping in the hostage building-- smart move, because we lost like 5 rounds in a row. Finally, my friends and I just decided to buy incendiary grenades to kill the hostages upstairs and grab the ones downstairs. And it worked out. I've also been on a team where, as the Ts, we killed all four hostages and hid around the map, waiting for time to tick down. Sounds cheap, but it's fun and mixes things up. Also funny was when my teammate only managed to rescue three hostages, accidentally leaving one behind. Solution: kill the last hostage and instantly win the round. And I like how things shift once the hostages are following CTs. It's very intense, either as a T trying to chase him down, or a CT dreading the Ts lurking near the rescue zone.
So I can see how hostage missions are unbalanced, but I just feel like they're a lot more dynamic. And thanks to the structure of the game, the teams switch sides mid-game so it's a bit more even. Although maybe the team that starts as Ts has an advantage since, if they play right, they only have to squeak out a few more victories as CTs to win the match.
In short: More hostage maps Valve!