What I've read on the subject - which admittedly doesn't amount to that much right enough so not claiming to be an expert on the subject - but what I've read on it seems to come down somewhere between the two extreme views. You do see some people claiming that it was a deliberate man made disaster where the British gvt tried to clear Ireland of the Irish - and others who claim there was no fault at all but that it was a natural catastrophe with no fault at anyone's door. Most of what I've read suggests it was a natural disaster which the gvt was slow to act on initially because of the laissez fair political beliefs that the market and society will right itself and the not understanding of the calamity that was taking place. When they did eventually act the situation was pretty overwhelming and still they were hampered by their own political dogma. This was the age of the workhouse etc where the idea that people should get food for nothing other than the fact that they need it did not sit easily with some of the ruling classes. Hence we'll dish out food it you build a road to nowhere but don't expect something for nothing as that'd be the end of society as we know it! So what I've read often does suggest the British gvt could be accused of initial inaction, dogma and stupidity - but not deliberate genocide. The quote from Welsh was in regard to that.

Devine (himself of Irish Catholic stock) writing about the Scottish aspect has some interesting thoughts as to why the famine in Scotland, though still serious, was much less severe than in Ireland. From what I remember he concedes that it affected only part of the country and that the numbers involved were more manageable than the much larger numbers in Ireland however he seems to make two main points. There was not the same stark religious/ethnic divide between all the people involved and the bulk of the land owners. Hence Scottish lairds and chiefs were more likely to help their own people when they could. Also the charities in Edinburgh and Glasgow sprung into action quicker than happened in Ireland. It still resulted in many deaths and of course eventually the depopulation of the glens but not to the same extent as the catastrophe that befell rural Ireland.