Firstly, no its not you riding ability that is making the surface difficult its the millions of tiny stones broken free from the hard clay dirt pack that is making it difficult to navigate corners at the grove. This however can be fixed relatively easily, next time you head out just take a broom and sweep your line (I keep mine behind the last corner, feel free to use it but please put it back and refer to dirt jump etiquette posted on rotorburn).
However I do agree that the maintenance of the grove is woeful but you need to realise that the guy who comes each fortnight probably has a check list that reads: Grass length, fallen trees, excessive rubbish, tap left on, erosion near drainage.... Ill bet you if he gets a 2 outa 4 result then the place is fit to ride, not requiring any maintenance. The fact is councils dont maintain jump parks (you probably wouldnt want them to anyway), riders do!
I just think the riders that ran the old grove got burnt! and they are rightly reluctant to put their energy back into the site. Mind you the grove has council approval and insurance so ill bet it will be allot tougher to bulldoze than freedom, I would advise any keen riders with trail building skills to put some thought to the grove, I reckon as long as there are still lines for beginner/intermediate riders, the riders would be given allot of room for development of more progressive lines, or at least turn a blind eye, after all they would have a fortnightly report of the sites deteriorating condition over the last year and a half without rider input.
End rant.