When you have hundreds of millions to spend year in and year out, your judgement can get cloudy. You lose the edge that GMs like Beane had where they have to budget and balance the checkbook. Instead, you can think, "Well he's good, let's get him". Epstein I'm sure, is an excellent GM, but in systems like NY, Boston, Philly, Chicago, Detroit, you can just try to sign anyone you think will help. A few bad contracts won't hurt these teams unlike if the Pirates were to sign Pujols and he got hurt, they'd be down and out for another 20 years.
This has been Bostons best decade since the 1910s. A lot of our fans are starting to act like entitled Yankees fans, and it sucks. I'd be happy for 1 or 2 WS appearances a decade, but let's be realistic, a lot of teams won't even get that.