There is a marked difference in scenic design between a theatre company with lots of money and a poor theatre company. This makes sense; the more money you have to invest in a set, the more elaborate it is allow to be and conversely the less money, the more sparse and improvised it has to be. For the moment, let us focus on those companies with less money.
Some of these companies do very well. These are able to put the focus on the acting and the technical elements that they do have. Smart companies in this situation will choose shows that are more abstract in thought where the environment can be implied rather than realistically recreated on stage. They will provide the outline and ask the audience to fill in the details; much like a children's coloring book.
However, there are still those companies that strive to do realism despite not being able to accurately recreate what is necessary on stage. Realism calls for us to have very few indicators that will remind us that we are in a theatre. Realism should function as close to the real world and you can on the stage. This includes all the walls you need, all the knickknacks on the shelves, and sometimes working appliances. The fewer details a design can include the more the illusion of the real world is shattered. If you don't have the time or the money to make sure all of these elements are in place, your production will be in trouble.
Companies should be self aware enough to be able to create an entire mise en scene. If a company is producing shows that the obviously cannot afford to produce, the company is in a serious identity crisis. If the production and performances are hurt by inadequate design, there is a lack of vision and oversight for the company. Too often do we see shows that don't even look like the team took the time to create an entire world, but rather just pulled out anything they had on hand in props storage.
Artists should hold themselves to high enough standards to make sure what they are producing properly conveys the story. This should be done to the best of ones ability - and if the resources aren't available, perhaps a different project should be considered. Is this story really worth telling so much that you produce a faulty product? I can't think of many plays that are.