Sometimes it is budget or just needing someone to drive it through a heavy process.
It is also not always worth it if you cannot show a real business case. The thing might help you and it might be worth it if you hack something together yourself but if IT is suppose to build something that is available, has support, has disaster recovery, is patched etc. it might no longer be easy to find the business case for it.
Exactly, to get professional IT resources you need to demonstrate a business case, go through many decision boards and budget allocations, defend it for months, and be ready to be pointed out if it doesn't reach its promises.
So in the end people hack it in Excel or Access. No need to ask permission, no budget issues, no blame if it's not great.
Also: little or no waste happened if it doesn't pan out. Your Access prototype doesn't seem to make you and your team work faster? Copy out the little data you've put in there to Excel, SHIFT+DEL the Access file, and you're done. You've wasted few hours. That beats wasting several man-months of IT time only to not use the result in the end.
Access is agile in the truest form. It lets you prototype and refine in an extremely tight feedback loop, until what you have is a working solution for your specific problems.
It is also not always worth it if you cannot show a real business case. The thing might help you and it might be worth it if you hack something together yourself but if IT is suppose to build something that is available, has support, has disaster recovery, is patched etc. it might no longer be easy to find the business case for it.