you could easily define a function with the language as input and a one dimensional output

e.g. the more characters the name has the better

F(Java)=5

F(C++)=3

with that definition Java is better than C++

A programming language could be measured by the efficiency of the language. Or the cross-platform nature of it. So a language can be good in some circumstances but not as good in others.

Interaction with PL can be measured the same way UI interaction is measured.

We can measure how long it takes to:

1) Write new program for given task
2) Extend task, modify that program
3) Add new feature to someone else program

We can measure how effective PL is as an interface.

There are plenty of examples of "objectively worse" programming language designs, i.e. ones that have have no silver lining. For instance, Javascript's and PHP's illogical "truthiness" concepts.

Whether being objectively bad means anything in real life is another question.