Edit: Maybe "fined" is not the correct term for this, but my understanding is that Ireland had granted Apple tax benefits which they shouldn't have granted. Isn't Ireland in the wrong here, rather than Apple?
The EU has now stepped in and clarified that Ireland should not have allowed this in the first place.
There is no direct impact for Ireland e.g. a fine but it will create uncertainty for others already operating in Ireland and those considering investment. This uncertainty can be very bad for Ireland for years to come, so there will almost certainly be a penalty, albeit an indirect one.
Would you feel that it is fair that you have to pay up, instead of the institution that wrongfully offered you tax refunds?
1) Apple would have sold their stuff in Europe whether they had to pay full taxes or not, they only wanted a discount. I would probably not pay for the solar panels because I can't afford them.
2) Solar panels are very expensive and would make a huge dent in my balance. That's not the case for Apple.