now some parents think that English grammar is more important than spoken English. Do you agree or disagree with that?

In my point of view, I disagree with that.Knowing grammar doesn't mean that u will also speak properly.If u have information on a particular topic, it doesn't mean that u will be able to speak about it fluently. Mastering in conversation and speaking skills makes u ready for all the circumstances in life, where u have to prefer speaking than merely gaining bookish knowledge of grammar. For instance, a job interview is a perfect example for what I mentioned just now. The interviewer will not see your grammatical knowledge, what and how much do u know about it, wheather u are the best in it. But, how u speak, converse and interact with him, makes him think that u are absolutely perfect for the job. And let it be in any field! Let's take another example. Like if u read something about swimming, and try to swim, u will surely drown at the first attempt. But if u have only a little knowledge about it and u try practicing swimming, gradually u'll learn how to swim and that too, faster than the one with a lot of knowledge. Same goes with the case of language. If u don't know how to speak well, definitely your grammatical knowledge will be of NO use. Speaking is the base of language. And it is by speaking only, that we can communicate with each other and not by grammar.
So, in my opinion, practicing conversation skills is more important than studying grammar.