Some of the problems that the author mentions in Perl5 are actual problems in Scala, for example the compiler and interpreter latency or start up time, the complexity of the language, the philosophy TIMTOWTDI and the bigger one is that other languages are getting better and better. Why just not to translate the philosophy of Perl to Scala, that is write a book translating the most common idioms of Perl to Scala. Good programmers could learn the Perl-Scala way in days, the real thing to realize is that today there is no single solution, you must master several programming languages, no one size fit for all problems.
I mostly agree and believe that before another abomination loosely based on Perl is written in Scala, people should learn Scala. However, Scala's syntax is also quite complicated, Scala code is often hard to read (far too much TIMTOWTDI there as well), so personally I favour Go as a modern alternative to Perl.