There is nothing wrong with using PEGs for SQL parsing, but this article (I didn't read the paper) presents flawed arguments:

- tech $X is from the 60s, therefore it is bad and/or outdated: one doesn't need to "disrupt" or innovate in everything to become modern. There are plenty of things from the 60s that still don't have a better replacement, and its OK to keep using it.

- "YACC-style parsers" clumps together parsers that are generated at compile-time, from declarative grammars, using LALR(1). But that's not inherit to the technique or algorithm: a parser can be LALR(1) from a declarative grammar and still extensible at run-time, or provide LL(1) alongside, or be built from statements instead of a grammar. There's nothing wrong with using PEGs over "YACC-style" parsers, but not for these distorted reasons.