He hates unitaskers in the kitchen because they take up finite space and money. These don't really apply to tiny free apps. It's like complaining about an extra key in a keyring you never use in a drawer you never open.
There is a 100x difference in size between different apps. If apps do little, they are often tiny.
A huge app that does nothing, that's a very different thing.
I'm an iOS developer. I have over 500 apps in iTunes ("Can you check this out please and tell me how much a menu like theirs would cost"), mostly not on my devices.
Unitask tools of the Alton Brown stripe are leaf nodes, not pipe nodes. They're roach motels, not highways. You check in, you don't check out. Design is typically monolithic, not atomic.
The Unix philosophy is for small, atomic, pipeable utilities that do a single task (more properly, subtask) in conjunction with other tools.
There are exceptions. including, say, web browsers. But where a browser is one level of monolithic app, it's generalized to that particular information purpose. A site-dedicated application is worlds worse.
No, he's articulating the Unix philosophy: tools should do one thing (knives are for cutting), and their user should be able to use that one thing for many different purposes, in conjunction with other tools.