I totally agree with you on this issue
One important part of the langauage is how to pronounce the sound. It is generally very hard for one to learn any new sound after a certain age. Therefore, it is extremly helpful if the child have access to multiple languages at the young age, so they will have a better coverage of different pronounciation. Simply put : if you didn't learn to say a certain sound when you were young, you probabily would never learn to correctly say it later.