Well Eric there can be many reasons for this. It is indeed frustrating that your wait time can be as long as your flight! If the flight is designated a gate, sometimes you have to wait for it. Reasons I can think of ? Not enough gates. Another the ground handlers/marshallers may be busy with other flights.(safety reasons aircraft must be marshalled in, you cant just park it as the pilots would likely get into trouble). Bureaucracy in a large airline may prevent openmindedness and overlook the fact that there is a vacant gate next door.
I remember 15 years ago at night our aircraft was broken down. I phoned dispatch and said there was a good one next to us. Put the passengers and more fuel onto the next a/c and away we went. Hope this helps
