I think one key to understanding his work is to understand how he helped make computers more accessible.

Among many things, he believed that "a computer should be just another piece of lab equipment." That they should be a basic tool.

Clark designed "small" computers, and it is no coincidence that the Linc was later marketed by Digital Equipment, a company all about the minicomputer that greatly increased computing accessibility. This company and the open academic culture that Clark was a huge part of led to greater accessibility software too. Would we have the world of Unix without the PDP series and the culture around it? Probably not!

Clark's role in computers was to be among the leaders of a sort of rebellion against monolithic and expensive computing, and his work led us the world of personal computing and open source software.