Microsoft co-founder Bill Gates had harsh words for Apple's iPad during a Monday morning TV interview on CNBC.

Speaking about the declining PC market, which reached record lows last quarter, Gates said that tablets were growing in popularity and it was "going to be harder and harder to distinguish products" that are PCs versus tablets. Then it was time for a plug for Microsoft's Surface tablet: it brings "portability of the tablet but the richness of the PC", according to the chairman. 

Speaking about the iPad, Gates said:"A lot of those users are frustrated, they can't type, they can't create documents, they don't have Office there."

Of course, users can type thanks to an on-screen keyboard and optional hardware accessory, but what Gates was getting at is the Surface's keyboard that integrates with the tablet. Office on the iPad is obviously up to Microsoft, if it ever wants to deliver. In the past, Gates has not been shy about his Surface praises. During a Reddit "Ask Me Anything" session in February, he had the Surface Pro early and called it "very nice". 

According to estimates from research firm IDC in early May, Microsoft has sold 900,000 combined Surface Pro and Surface RTs during the first quarter. This moved Microsoft to a fifth place spot, or a 1.8 per cent tablet marketshare for the quarter.

An interesting fact from IDC was that the more expensive Surface Pro made up a large amount of the 900,000 total Surface units. To compare, Apple shipped 19.5 million iPads  during Q1(compared to 11.8 million in the same quarter last year), keeping its longtime lead in the tablet space.

What do you think about Gates's comments?