in reply to We don't need a cat
A concatenation operator isn't just about "small syntax" as you put it. It's also about how you think about the operation (Perl's supposed to work for/with your brain, right?). If composing a third string of two others works in your head as interpolation, then there's no problem with that, but if you think about it as sticking one string on the end of another, an operator would be more appropriate for that brain-metaphor.
nemo accipere quod non merere
In Section Meditations