LISP js easy to parse, transform, build clean-slate, verify, and do fast. My first 4GL tool was a BASIC w/ macros compatible with C and C++. When converted to LISP, it was vastly easier to do transforms and macros plus productivity boost with incremental, per-function compilation. Turns out, Julia did something similar by converting the source into AST's that are LISP expressions with compiler being femtolisp.

Far as safet, you can build checks into your code for protection or use a typed subset of LISP (eg Typed Racket). Shen goes further by embedding whole sequent calculus for custom, per app/module, type systems.

So, not saying LISP is ideal for compilers but does have some ideal and good attributes. Ocaml is my default given it combines conciseness, correctness, decent performance, ease of learning, and some helpful libs.