The poll was in conjunction with two other organizations. I don't believe they conducted the poll themselves. That having been said, I agree with you that it is appropriate to question polls. I personally don't participate in them when contacted.
I don't trust polls, but I still read them. While they are frequently wrong, they often are informative. For example, the WSJ poll shows that many people do not trust Biden. The numbers might not be accurately, but the poll is useful in that it points to a communications problem that the Biden campaign needs to address.
Thanks for the comment.