Sometimes, if the tools are designed really well, they do combine. Witness the success of Unix pipelines, or the nigh-magical ability of TCP to work over Ethernet, Wifi, a modem, or whatever other complex systems people dream up.
Being able to combine complex systems is a good thing, and it shouldn't be disparaged as unrealistic.
Applications communicating via Unix pipelines indeed do frequently combine, albeit rarely without great amounts of awk/grep/sed glue and reimplementation of parsing machinery in every link in a chain.
I don't say that pipelines are bad, it's just sometimes we want more structured data format than flat text.
Also, Unix pipelines are currently in decline, and Unix itself is less Unixy than it used to be.
Neither unix pipes nor TCP are particularly complex, and it is their simplicity that lets them be combined -- easier to combine a hammer and an axe than a nail-gun and a rotary saw.
Being able to combine complex systems is a good thing, and it shouldn't be disparaged as unrealistic.