I think this problem derives from the nature of and incentives of people. What happens is that certain managers (and founders) have derived their success from pushing certain directions that have added a lot of value.
Usually long term initiative take a lot of domain knowledge and a specific set of connections. When something new becomes more important, they risk losing their personal position since they may not be the best person in terms of knowledge and connection to carry out the new direction. Instead they try to use their accumulated power to keep their direction supported even when it's not in the interest of the business for as long as they can.
To address this, perhaps there's merit in rewarding timely exits and somehow punishing people that have dragged things out. However the most that companies can do is usually just fire someone. And at that point they have probably sucked the company dry of the value they can personally extract.
Usually long term initiative take a lot of domain knowledge and a specific set of connections. When something new becomes more important, they risk losing their personal position since they may not be the best person in terms of knowledge and connection to carry out the new direction. Instead they try to use their accumulated power to keep their direction supported even when it's not in the interest of the business for as long as they can.
To address this, perhaps there's merit in rewarding timely exits and somehow punishing people that have dragged things out. However the most that companies can do is usually just fire someone. And at that point they have probably sucked the company dry of the value they can personally extract.