Unionization will not suddenly make the business respect IT. Do you want what all the other big career options have then start acting like a professional.
Someone earlier said that if a normal engineer knows how much guessing an IT engineer does then they will be ashamed of calling them engineers. Well then ask yourself why are you making so many guesses. It is shocking to me how many people implement systems without putting them in a test environment. Do you think that the Petronas Towers were built without doing extensive modeling ? Well get that attitude into IT and maybe the business will start respecting you more.
Also for those not familiar with ITIL, IT is there to support the business. IT is not the boss of the business.
And again be professional. Should you be called into a meeting with management about a major project that you are busy with, try and be on time, do not show up carrying a can of 7up and God help me next time I see some idiot pitching up with a food stained t-shirt and expecting me to treat him like a professional adult. If you need a bib to eat then I will treat you like a child and make you stay behind until your job is finished.
And just for the record I am a techie not management but I have been in enough meetings where things like this happen. Finally for management stop hiring the smooth talking fly by nights or PFYs that I am sure is just out there to screw up my systems because they promise me at home when they have problems a factory reset of the router does the job. In short management should learn IT before they hire anybody else.
Do this and IT will become respected and there will be no need for unions.
