That is a really good point! I can't say i use mine frequently, but i do use it. My thoughts on it are that is makes a great tool. Word repetition is bad in writing. Once you have used a word, and want to use it again in the same few paragraphs, you need to look to see if there is another way to say it. Substituting a word that way can save it. Sometimes I want to say something, only to look at it and realize it has been said exactly that way in a hundred other books, so i will want to look at changing it. A thesaurus is a great way to do it. Takes it from being a cliche.
On the other hand, i refuse to use the thesaurus to make myself look smart, lol. My writing has to be me, to a certain extent. If i am using my thesaurus to change up normal, every day words into their fancier counterparts, then my writing is no longer me, just who i wish i would be, lol.
So it has its uses, but i have a line i wont cross with it.