You Don't Need Every Part of ITIL
BECTA, the British Educational Communications and Technology Agency, developed the Framework for ICT Technical Support (FITS) from ITIL. Adapted to the unique needs educational institutions, FITS is ITIL tailored to a specific requirement.
Then again we have to consider homespun solutions. Any significantly mature IT organization will, by default, have stumbled into the issues that ITIL addresses. These organizations evolved solutions on there own. It turns out that these homespun solutions often (and without the malice of foresight) mimic those described by ITIL.
Much of ITIL is simply common sense, and natural selection and corporate evolution means some companies would have naturally uncovered these best-practices. Those that did not are using one of the other options described, or have already gone extinct (e.g., out of business.)
An Educated Consumer
Clearly then ITIL is not for everyone. You dont need everything in ITIL. You dont have to mature everything you do implement to the complete description in ITIL. And there are alternatives to from which to choose.
Further, ITIL does not stand alone in any implementation. It lives within a collection of standards, best-practices, management philosophies, and legislative requirements. ITIL itself is not a single thing but, as it very clearly states, The IT Infrastructure Library documents industry best-practice guidance.
So, how can you tell if ITIL way is right for you? You have to learn about it, study it, and talk to those who are doing it and those who chose not to do it or have done something else. There are lots of implementations out there. Get involved. If it seems to suit you, then use it, or modify it, and use it.
In any case, given its momentum, which simply cannot be from just a couple of evil vendors manipulating the media, you need to know about it. This momentum is a direct result of the cost control, business dependency, and legislative issues surrounding IT.
Use ITIL for what it is, a collection of accepted best-practices, international standards, academic research projects, and popular industry texts assembled into one possible order of presentation.
Think of it as a guide book, not a playbook. Take what you need when you need it. Modify it if you want or need. If appropriate (and it is not always appropriate) use it as-is.
You know the old marketing saw An educated consumer is the best customer. Its never been truer than now and never applied more than it does to ITIL.