Conventions exist in every language. `car', `cons', and `cdr' are also part of certain standards (e.g. RnRS). And, honestly, they compose a bit better than `first', and `rest' for combinations like `caddr' and `caaddr'. I suspect that you're going to be even more unhappy with those constructions.
The same can be said about older languages like C, which also have standardized notations.
Why fix what isn't broken?