there are no bad languages, just bad programmers.
There are, however, languages that make it far easier to write code that is less readable and harder to maintain. As a specific example, compare Fortran 77 with Fortran 90. I can write the latter without any need for numerical statement labels. I can write a straightforward "DO WHILE" loop in Fortran 90, while in Fortran 77, I'd have to use the dreaded GOTO to get the same effect. Aside from basic stuff like that, I can write formulas in Fortran 90 with whole arrays, which can really help readability. In short, it is far easier to write clear code in Fortran 90 than in Fortran 77.
Do they seriously think that if those models were written in C, Java or Perl they would have been magnitudes better?
Heck, yes! For one thing, in any of those languages, separation of code and data -- something which spreadsheets actively discourage -- would be much easier.