The main reason I am against it is twofold, firstly if you are going to stop games for any period of time in order to "get the big decisions correct" then you have to get them correct, regardless if thats the tech or the person behind the tech, they are one and the same. The fact that it came in with fanfare of being needed and its frankly been proven to also get things wrong makes it laughable.
Secondly where football and tech do not work together is that decisions such as handballs are open to interpretation because technology can not define intent. A frozen picture makes every handball look guilty so you need someone to make the call on the intent, thats why the same incidents are getting different decisions because its humans calling it, so really you could have just left it to the ref on the pitch to decide.
I was always one for leaving it up to refs and reinforcing a respect the refs message, there are human errors in the game, the refs were probably the least of the issues if you compare them to player mistakes or managers making shocking decisions.