It's probably more productive to change the way to think about this particular situation.
To address the situation:
To me it sounds like you're currently running into the problem that journals are highly selective. Many papers get rejected, all the time. The fact that your paper gets rejected several times in a row does not necessarily imply that there is no publishable idea within the paper. It may be that the current version of the paper is not quite good enough for publication right now, for reasons of writing, or experimental setup, or embedding in related work. Editors and reviewers may see this as a bigger deal than you, and it's quite possible that they're wrong and you're right (as well as vice versa). But it may also be that the paper is indeed good enough in its current form, but you just may have run into a few sets of reviewers/editors who read your paper on a bad day.
The point is: what you are observing right now can easily be explained by bad luck. Take a good hard look at your paper in its current state, and be honest with yourself. If you are still convinced that the paper is good enough for publication, then don't let a few rejections stop you: dust yourself off and try again.
To answer the question as asked:
In practice, editors and reviewers have a direct interest in keeping the process fair and balanced. In the minds of most scientists, this fairness is what makes science great, and the reputation of a journal would quickly suffer if famous authors get preferential treatment. Therefore, I don't think that anybody would consciously bias their journal towards famous authors.
It is possible that there is an unconscious bias. Suppose that an editor just had to reject thirty papers of cranks claiming to have unified quantum mechanics and general relativity, or (dis-)proved that P=NP. At the end of a working day like that, it is not impossible that this editor is slightly less ideally predisposed towards the 31st and 32nd paper by an independent scholar. They should be neutral towards any paper reaching their desk, but it is not entirely impossible that unconscious bias plays a small part.
Notice that it is impossible to completely eliminate unconscious biases from the reviewing process. Earlier today, I happened to receive some very good news in my personal life. If I now proceed to review a paper this afternoon, it is quite possible that I am unreasonably friendly towards the paper, simply because I am smiling back at the world which is smiling at me. If my fellow reviewer happens to be in the middle of a messy divorce, they will be less friendly towards everything, including papers they happen to have to review right now. This human factor cannot be completely eliminated from the process (even though every individual reviewer or editor will try their best to do so), and therefore authors should also take the outcome of a reviewing process with a grain of salt.