Indonesia is trying hard to bring their aviation standards (both engineering and operationally) up to international levels. The fact that I have new Airbus aircraft in my fleet and my competitors just took delivery of more new A319s and the fact an Indonesian airline was launch airline for 737-900 shows they are trying to change for the better, even if it is very very slowly!
There are a number of us 'bules' working in Indonesian aviation, so it is not closed to foreigners and I would not say they protect their own any more than any other country, but a foreigner is going to cost a local company here a lot of money in tax, housing and USD salaries so naturally they want value for money. (ask any expat in the middle east the same question about local protection). If you have something they need, they will bring you in and the packages here can be competitive.