You have become a bit spoiled, but the abrupt change in philosophy certainly can perplex fans and change expectations. If my team had the top overall farm system and then dealt it all away to win now, my expectation would be that they won and showed well in the postseason. The sox have won in the regular season, but appeared entirely unprepared for the playoffs. While back to back AL East titles is awesome, winning but a single game in the playoffs over 2 years is not. Plus, when the future is bright, it takes the sting off the losses. When you know you're facing a cliff, the urgency is there to win. Most sox fans can remember vividly the last place finishes and when you are staring a cliff in the face, know that you're going to get back to that point again. Relishing a title in that time makes it all worth it. Watching opportunities wasted makes it all a waste. Its just anxiety management
Also, watching the Yankees rebuild in half a season and then get within a game of the world series tightens up that urgency