From my own professional experience, I'd say it's got more to do with the artificial delivery constraints that come with the mandatory annual and quarterly financial reporting of publicly traded companies. They announce their yearly results to the market and next years IT budget is broadly defined as a portion of the previous year's profits.
Everything is planned & tracked as a portion of an arbitrary 12-month time frame & the internal politics means each department are competing for funds on a "use-it-or-lose-it" basis. If you've never sat in on department/geography/company-wide governance forums where they agree next year's "change management" budget, the basic format is you present a business case & cost forecast based on FTEs over the expected duration of the project, all the mandatory regulatory compliance projects get approved automatically and the remainder of the budget is set based on how well each middle-manager can defend the interest of their department. They have a final number for total approved spend & approve as many projects as they who's forecast cost fits into that, Tetris-style, with a flat 20% contingency spread across everything to account for the fact that historically, trying to plan in this way is so inaccurate that it's basically a series of pseudo-random guesses. It's worth noting that even stuff badged as "Agile" is funded & budgeted for in this way.
Every programme I've been involved with has had some variation on "we can't start work on X in that month, because it won't finish until February and will cannibalise part of my budget for next year".
Unfortunately, given the economic & political status quo this problem is impossible to solve (but for the libertarians reading this, an interesting example of the 'higher order' unintended consequences of sincerely designed industry regulation.
Everything is planned & tracked as a portion of an arbitrary 12-month time frame & the internal politics means each department are competing for funds on a "use-it-or-lose-it" basis. If you've never sat in on department/geography/company-wide governance forums where they agree next year's "change management" budget, the basic format is you present a business case & cost forecast based on FTEs over the expected duration of the project, all the mandatory regulatory compliance projects get approved automatically and the remainder of the budget is set based on how well each middle-manager can defend the interest of their department. They have a final number for total approved spend & approve as many projects as they who's forecast cost fits into that, Tetris-style, with a flat 20% contingency spread across everything to account for the fact that historically, trying to plan in this way is so inaccurate that it's basically a series of pseudo-random guesses. It's worth noting that even stuff badged as "Agile" is funded & budgeted for in this way.
Every programme I've been involved with has had some variation on "we can't start work on X in that month, because it won't finish until February and will cannibalise part of my budget for next year".
Unfortunately, given the economic & political status quo this problem is impossible to solve (but for the libertarians reading this, an interesting example of the 'higher order' unintended consequences of sincerely designed industry regulation.