The conclusion I reach for some people in this position is that their "growth investments" will now have to do all the heavy lifting as their deposits will have a negative expected return after DIRT and inflation are taken into account.
For those unwilling to hold growth assets, the phrase "financial repression" has been used to describe their position. Since their "choice" is really between either having to invest with the possibilility of a negative return or to simply accept the inevitability of a slow and creeping loss of personal wealth and associated purchasing power on an after tax basis due to inflation.
Clearly, therefore both courses carry some risk.
The key to this problem as I see it is to determine a "Goldilocks portfolio". How little risk do I need to take in order to create a stream of income which is subject to income tax (plus USC and possibly PRSI) and capital gains tax rather than DIRT or Exit Tax and offer the prospect of maintaining the real value of my capital, within the constraints of my willingness and capacity for investment risk.
The alternative for many people is simply that not investing at least some of their capital should now be considered to be "recklessly conservative".
To save at all on a low income is hard enough without this.