Anyone studying psychology will have to learn about and understand research methods and statistics. The fact that research methods and statistics are nearly always compulsory within a psychology course should immediately alert you to their importance.
They matter because in order to critically evaluate the findings of key studies you need to be aware of how the data supporting those findings came about; and you can't seriously hope to conduct your own research with confidence unless you have a clear idea how to design, execute and analyze your investigation.
When I first started supervising research dissertations and psychology projects I came across a large number of students who refused to consider doing anything other than interviews, whether such an approach was appropriate for their particular investigation or not.
The most common reason for this was the incorrect assumption that qualitative research methods (text based) are much easier to understand and carry out proficiently than quantitative (number based) research methods.