The least I could do

‘THANK YOU for cleaning the kitchen.’
‘It’s the least I could do.’

Why is it that I find this phrase so abhorrent? Is it the implication that the person doing the favour would rather have done nothing at all, but when it came down to it they chose the simplest, least time-consuming option? The one that put themselves out to the minimal extent?

Here’s an alternative response that I prefer:

‘You’re welcome.’