Now there are things you can outsource and there are things which you cannot outsource.
Aircon and facilities management (electricity/diesel/UPS etc) can be safely outsourced since those technicians don't always need to be available 24x7.
However, critical systems, such as databases, NAS units, core routers etc, all of these are critical assets and will need 24x7x365 babysitting, because you don't know what will happen.
And when the brown stuff hits the big windmill, you are entirely dependent on your outsourced IT team, who will only be able to respond in 3 to 5 hours (or worse).
Worse still, they will have to drop other clients in order to attend to your brownware period. First they will send their appy or trainees, which will take a shufty at your stuff, brown themselves, and call for more experienced persons to come out.
WHEREAS if you had your own onsite IT team, they will be able to respond promptly (save for those members who are on leave). And even then they will know who to contact for assistance. And if you have been paying them good salaries and are on good terms with your own IT team, most team members on holiday may be prepared to go the extra mile and try to assist remotely where possible. (But on the other hand, if you're stingy with salaries and bonuses etc, then the members who are on vacation will give you a big GFY ~ which you deserve ~ and leave you to handle the fallout best you can). Also, you have the final call on quality - you can select the best persons for your job, and know what they can (and cannot) do - and have more control over your own IT.
After all, most beancounters does not realize that "outsourcing" is the same as "timesharing" - the sharing of resources such as IT techs, IT sysadmins and IT gurus... and there's absolutely no control over who the contractor will call in to try and bodge your systems even more. Also, another thing to consider is if an contractor have an emergency to deal with, and all of their IT geniuses are attending to that emergency, and you come along with your own emergency, then you'll have to wait for the first emergency to be cleared first. Or am I wrong here?