This unfortunately all comes down to what you mean by "basically" and what they meant by "limited".
I think what they said is closer to the truth. I've used flex/bison a few times to create simple languages, and as long as they're parsed correctly, which is quick/easy to roughly check with a REPL (mine were in that form), conflicts can be ignored. Mine worked fine. It was a joy to use - having both flex and bison program windows open, plus bash to run the makefile, I could add a feature and test it within seconds. I'd say I have very limited knowledge of parsing, but read a few flex/bison books, enough to grasp what that message means. It's not necessary to have no conflicts, from what I understand. And it seems you have a more....professional language in mind, like in a commercial situation.
But then again, Yacc/bison isn't very important because it allows etc.... (i.e. that's not the reason it's important)
I think what they said is closer to the truth. I've used flex/bison a few times to create simple languages, and as long as they're parsed correctly, which is quick/easy to roughly check with a REPL (mine were in that form), conflicts can be ignored. Mine worked fine. It was a joy to use - having both flex and bison program windows open, plus bash to run the makefile, I could add a feature and test it within seconds. I'd say I have very limited knowledge of parsing, but read a few flex/bison books, enough to grasp what that message means. It's not necessary to have no conflicts, from what I understand. And it seems you have a more....professional language in mind, like in a commercial situation.
But then again, Yacc/bison isn't very important because it allows etc.... (i.e. that's not the reason it's important)