Politicians will always listen to those people or organisations that say exactly what they want to hear. The fact that organisations like the OECD or ESRI painted nice and rosy pictures and that they were/are given so much credibility is a very handy thing for politicians to use. When things go wrong, they can hide behind the advice given by "reputable" organisations.
Economists of the Austrian School were warning of and predicting the crisis way before it happened, but even to this day governments are not paying attention to them, because they are saying what politicians need to hear, not what they want to hear, which is that whether socialist or conservative, interventions by governments in the market will always lead to crisis. Their solution is smaller government, spend less, tax less, and do not go into debt; anyone know a politician who likes this idea?
I believe blaming Bertie is an easy option. The real issue is that no matter what side of the political spectrum the government had come from (FG, SF, SLFD, FF, Labour), the government would have interfered in one way or another, and all interference results in disaster. Unless I hear a politician say that during the boom the right thing to have done, would have been nothing at all, i.e. not to interfere with the housing or financial market, I will not believe that they would not have caused the same mess.
Take for example affordable housing, mortgage interest relief and stamp duty rules for first time buyers. I have no doubt that any other party in government would have introduced similar schemes "to help first time buyers who are priced out of the market". All this did was fuel the demand for houses, resulting in higher prices. This is not something you need the advantage of hindsight for, this is basic economics.
Bottom line, I believe all governments have and still are behaving in a grossly irresponsible manner.