Indicating

It's cropped up in various places - the lack of people indicating in cars, why though? I really don't get it and I'm getting fed-up of it all. I'm fed-up of entering Vale Road from the town and pulling out to overtake a slower vehicle as I move into the third lane (indicating of course as I'm changing lanes) only to find I'm being cut-up by that car who has also decided they want to be in that lane. I'm fed-up of people coming down into Gilgal, Mitton Street or Lion Hill and veering across the lanes. I'm fed-up of overtaking slow traffic stopped at the Birchen Coppice lights in Minster Road only to have a car pull out in front of me and force me to an abrupt slow-down.

I'm fed-up waiting to enter an island only to have the cars I've been waiting for taking my exit; I'm fed-up of thinking I can enter the island only to find the car that appeared to be taking my exit is in fact continuing into my path; I'm fed-up of cars in the right-hand lane of an island exiting onto a dual carriageway into the left-hand lane when I'm trying to turn left into it.

To put it succintly I'm simply fed-up of it all and I want to know why this seems to be becoming more and more prevalent on our roads?