Sorry I didn't know critique and beta readers are the same. I thought a beta reader was actually a writing partner.
Story (I'm just full of them). I wrote a novel. I let a friend read it. She "ooed" and "ahhed" over it, and I thought, "I must be a great writer. Look how she responded." I immediately started sending queries, expecting the same response from agents. At that point, I thought my job was to sit back and wait for agents to start fighting over who'd represent me. Didn't happen.
After about 30 rejections, I found a beta on AW, someone who has since become a very dear friend. She asked to read. I sent, fully expecting her to send me a glowing report. She didn't. My heart practically stopped when I got her response. The first thing she said, "The book starts too soon." Her comments became a long litany of things I'd done wrong. At first I resisted. "Hey, this is my book, and I'll write it the way I want to." After a while, I gave in and really started listening to what she had to say. Now, a year later, I have a rather impressive agency asking for some revisions and a resubmission. I also have a second novel that's nearly finished.
If I'd had a 'real' beta instead of a dear friend read the book first, I may not have had the 44 rejections. I would have had some. That's inevitable, but I'm confident that I would certainly have had more requests for full manuscripts and/or an offer of representation by now. You'll fare better than I did if you take the advice this not-so-novice writer. First books are always a hard sell, and whoever said we don't see our own flaws is absolutely right.