Because things have to immediately get better for it to be the right decision, right? Mindsets like this are what keeps bad franchises from growing. Reminds me of when the Raiders went 8-8 two consecutive years in '10/'11. By far their best years in nearly a decade. New GM comes in and cleans all the bad contracts and culture and team is awful again the next few years. Raiders fans were calling for Reggie McKenzie's head because the team finally put out a decent product and he scrapped it. Now he's viewed as a brilliant GM and the Raiders are possibly the most promising team in the NFL with impeccable culture. Had he have kept the roster and coach, they probably could have squeaked out a few more mediocre years and temporary (relative) happiness among the fans at the cost of mortgaging the future. Instead, he weighed the options of being temporarily decent with a bleak future after, or gutting the team and making decisions to become formidable in the future. He chose the latter and, as is typically the case when that option is chosen, it was correct and now as a Raiders fans, I am seeing the fruits of that painful 4/5 year process come about.
Completely different scenarios, but the idea is the same. The best decision for a good future is generally going to be hated at the time by fans because everyone wants something right now, not a lot of fans like thinking 4 years down the road if it means being bad right now. But when that time hits and you have these blossoming players instead of that one supreme talent, that ONLY talent and one who was only going to sustain mediocrity, you'll look back and be happy you have something to look forward to instead of an aging, declining player, no cap space and no young talent to look forward to.
I was part of the group calling for Reggie's head during that process for the Raiders and I it was quite the learning experience. I'll take the awful now and a bright future instead of being slightly better than awful and no future.