Can we trust such papers published in such journal?

Becuase you can pay to publish it, it simply does not make sense! We should ask a question who will benefit more from such deal. 

Scientists as a whole use the tax payers money to do reearch, and this research would benefit the tax payers or society in an ideal case. However, scientists pay the journal to publish their research. In this deal, the people who run the journal make a big money or profit. The scientists publish their their research in the journal to get their reputation so that they use such reputation to get more fund (money) from the funding agency (paided by tax payers via the government). This circle would continue, and continue. From such a circle, the tax payers benefit nothing and cannot get anything!

I think the fund agency should look into such deal - that scientists pay the journal to publish their research! Otherwise, the tax payers will not be happy with the 'paying the journal to publish trash research'. Why should the public fund these gabbage research?