There are matters of degree here. If you can accomplish what you have to contribute to the world without isolation, and be equally effective, it is probably more moral to do so. But there is a difference between 'not perfectly moral' and immoral.
Most folks have argued that there are times when isolation is necessary, or where it pays off, and therefore there is nothing wrong with it. That does not follow. From most viewpoints, there is nothing wrong with eating steak, but one can still question whether it would be more moral not to. Or whether there is an optimally moral amount that most of us exceed.
I would argue that connection with society has an inherent moral value, whether or not it promotes 'progress' of some variety. Simply being available and contributing your perspective to the mainstream process to the degree this is possible creates a different society, and any given perspective may in the end be a deciding contribution.
To the extent that your perspectives are largely redundant, or simply balance out other existing perspectives, this is not a concern. But I would argue that being a person who contributes no genuinely unaccounted perspective is probably doing less than one might as a moral individual.
There is an obligation, when born into a society to offset one's burden upon it. Part of that burden is intellectual, even if you are a common person with no vaunted intellectual ambitions.
This is basically the "The existence of democracy, and the sacrifices implicit in maintaining it, imply you should vote" argument at a more detailed level. (So I can see how that puts me in a minority, given how Americans vote.) You cannot participate in the process if you aren't there, and the process itself has value, even if we cannot discern it. (That last proceeds from basically religious motivations, so I cannot defend it well. But I think a lot of moralities implicitly assume it.)
At the same time, if society, its structure, or the availability of its products makes you less able to express your own gifts, or if you are the kind of person who degrades society inadvertently and cannot help yourself (I have known a lot of drug-and-or-sex addicts for whom both of those things are true, and an equal number of 'schizoid-construction' deep thinkers) you may actually be more obligated to stay away.
Isolation is also not necessarily physical. I feel that modern society, although at the same time insanely gregarious, produces too much personal isolation for the good of the whole. Too many subtle contributions are suppressed. Physical isolation that produced less emotional and intellectual isolation would not be isolation in the sense of this argument if the result had any chance of making it back into society.