They're right... and many other corruptions of modern American politics could be lessened if incumbents weren't so protected.
We could easily, with today's mapping technology, make contiguous but completely partisan-indifferent districts. As an extreme example, California's 53 districts could each be horizontal stripes, having only latitudinal straight lines as drawn borders, with equal populations. (They'd be wider near Eureka, thin near big cities.) Odd, and tough on campaigners -- but still an improvement over today's noncompetitive districts.
Other algorithms could satisfy 'compactness' as an ease to campaigning, as appropriate -- so long as partisan data is never fed into the algorithm as an input. (So far, the only deployment of advanced demographic technology in practice has been by the parties to assist their gerrymandering.) The Wikipedia article on gerrymandering discusses some possible algorithms.