theory does influence the results given simply because theory influences the way it's tested.
we don't just LOOK at things anymore. we poke around using instruments. what if it turned out that the theory used to build our telescopes for example, was flawed. this is extremely unlikely and not worth worrying about on a day to day basis. however it is important to know that nothing is EVER tested in isolation, no theory can be extracted from its fellows and tested independently.
sure, most of the time evidence that passes the test of repeatability by different people in different places can be *treated as* being objective. but it still has a possibility of being flawed. it is possible for a hundred people in a hundred different places to all do the same experiment and get the same results (and i've done lab experiments, so them all getting the same results seems highly unlikely, hey the equipment actually working seems highly unlikely) and for every single one of them to be basing it on a flawed assumption.
I'm not saying that science should change, or that there is a better way of deciding which things are good evidence. because I don't think there is one, and if there ever is then I'm sure that that won't be objective either. However, what I am saying is that the dependence of observation on theory should be more widely known, and that science shouldn't take such things like "as close as we can get to objectivity" as "objectivity"