Those famines were not created by the Victorians. They were all originating in natural disasters that the locals were unable to handle for themselves. The claim that the Victorians did something immoral is an ideological one, as it's effectively a claim that even though they did try to help they could have tried even more - and not rising to that level of assistance (determined arbitrarily by moderns who were not there) was somehow evil.
This view is usually also implying without stating that it is uncharitable or morally wrong for governments to not suspend free markets and impose a communist planned economy the moment there's a natural disaster. That's a highly controversial view (and a wrong one if you want something that works), but it gets slipped into criticisms of the Victorians all the time.
This is the same logic that says shutting down USAID killed people. It's an attempt to convert the possibility of charity into a hard moral obligation - but if accepted, that would make it no longer charity.
Specifically:
• The Victorians did provide aid to Ireland during the potato famine.
• In India they did also provide aid, organized relief camps, suspended tax collection, and spent large sums of taxes and Victorian Brits made large numbers of charitable donations. It didn't look so different to the various aid campaigns for Africa in the 20th century.
• There is no such thing as the "late Victorian Holocaust". That's a concept from a book written by a Marxist in 2000 that argues that capitalism is the same thing as genocide, and frankly seems incredibly offensive to survivors of the actual holocaust.