Dunno doesn't seem like this in London - the small parties are still rocking - ups and downs but still a vibrant scene.
You may just need to do what you are doing as a bigger collective representing the whole local scene in a specific genre and put on good parties - rather than lots of independant promoters.
Maybe all your local artists have been seen too many times by too few people that are into the scene around you. People may just want to see somebody else.
Are the 'big DJs' playing a different style that is just more popular that the sound you are playing?