This isn't a very good article. First of all, this has to be the most rehashed curiosa topic about Lisp, ever. Secondly, "keeping in touch with tradition" isn't a shallow thing you do for fun---it is both about identity and about the ability to read and reuse code, even though it is decades old. And thirdly, the reason you keep car and cdr isn't only about tradition, but also about the ability to quickly reach into nested lists:
(cdaddr '(1 (2 (3 4 (5) (6 7) 8) 9) (10 1 3) 3)) => (1 3)
Without these oldies, you would have to write several combinations of first, second etc. and rest, or some combination of first/rest and nth n list.