Unless you can show absolute numbers, you can't call it a "dip".

Like many in various industries there has been a huge push to support mobile, and thus the effect the larger % of the population who use mobiles vs pc's comes into effect

Why is that? He's just pointing out that the dwindling numbers are not necessarily because of a desktop market share decline but because of the growth of mobile. We're seeing this everywhere.

The point is, as a _share_ the numbers are dwindling, but we can't tell from the share numbers whether the _absolute numbers_ are dwindling, stagnant, or still growing (albeit slower than mobile growth).