As a former reviewer working for a very renowned research institute in Europe I can say: Peers typically don't get/take the time to do their job right, and often outsource the job to less experienced people. Reproducing results is a very expensive and time consuming job, which means: unless it is it won't happen. You must be lucky if the reviewers have at least read the paper till the end. Quite often the review happens by people who are "no experts" in the field of the paper. For many conferences, papers with a bad rating still pass because there are not sufficient good papers, or if it is easy to guess the institute the authors work for, the paper passes without proper review.
Once our institute had a paper rejected, but my boss -who was in the review team- managed to get the paper accepted anyway. High profile conference in Electronic Engineering.
As a former paper author I can say: If your paper is rejected for one conference, you simply resubmit to another until it is accepted. Publish or perish is the holy grail of research, something many bosses will make very clear to you, and quality is less important. You don't write a paper because you have results, you write a paper because this or that major conference has a deadline in two weeks. I have a few paper on my name I am ashamed of: Omitting the bad results in the measurements, compare with competitors only on the features you know you would win because the comparison doesn't make sense at all, bragging about results which are very bad, but you hide that by not comparing to (avoiding any reference to) competitors which are better.
As you might understand, I quit the job. I left research and never ever want to have anything to do with it anymore.