And there was plenty of food in Ireland, it got all shipped to England.
It should be remembered that whilst Britain was the most powerful and richest nation in the world during the 1840s and 50s it was still by modern standards, a developing nation with plenty of poverty of its own, and the famine had been ongoing for years by 1847 when famine fatigue had set in, and during that year there was a financial panic caused by the collapse of the railway boom that threatened to turn into a severe economic crisis that could have overwhelmed the country and caused a run on the banks.
In that context many in Britain, ignorant of the extent and reasons for the continuing crisis in Ireland started to resent continuing to pay for famine relief in Ireland and understandably thought that some of the wealthy absentee landlords (many of whom lived the high life in England) shouldn’t pay more of their fair share to help with a local crisis.
The unintended consequences of raising taxes on these landlords to pay for famine relief was that they exported more cash crops to pay these taxes. It may have been the wrong move, in hindsight but it was not a deliberate attempt at genocide, more shortsidedness and the failure to consider a policy which might have done more harm than good.
That’s what I’ve read, too.