And a specific counterpoint:
Seriously, how are we supposed to otherwise believe that Han can talk with Chewbacca, Greedo, Jabba, and every other alien he meets? Jabba needs an interpreter (Threepio) to talk to Luke, the Princess, etc.; but Solo can talk English to him and Jabba can talk Hutt back? Han’s communication abilities fall well outside any “he was raised by Wookies” ad hoc hypotheses.
I think it’s quite reasonable to believe that a trader and smuggler would, in fact, be fluent in multiple languages. Hutt himself would be at a huge disadvantage if he didn’t understand Basic, so he can understand Solo just fine; and Solo would be at a huge disadvantage himself if he only spoke Basic. Four languages is not a huge burden, especially if we don’t necessarily assume that he speaks them with complete fluency.