As a moral system, rigorism in essence holds that, if an action might be forbidden, it is forbidden, unless everyone agrees that it is not forbidden. You might say a rigorist teaches, "Better sorry than unsafe." (There are better, but more wordy, definitions available.)
A lot of pro-life American Catholics seem to be rigorists on life issues, judging by what I've read of attitudes toward incremental improvements in abortion laws, artificial hydration and nutrition, and medical research ethics.
The risk of rigorism is that it might forbid what is permissible. A rigorist might find himself condemning as sinful something God does not regard as sinful. A Catholic rigorist, if he is more rigorous than the Church, might find himself condemning as contrary to Catholic teaching something the Church does not regard as contrary to Catholic teaching.
I think, in the general case, the Church permits a variety of viewpoints, and She permits holders of those viewpoints to tell each other they're wrong. What the Church doesn't permit is for holders of different viewpoints to tell each other they're not Catholic.
There may well come a time when the Church pronounces on a topic, forbidding certain viewpoints either morally or prudentially, and those holding a viewpoint can certainly urge the Church toward their preference. But what is obviously true to a proponent is often not so obviously true to the Church, and we should recognize that the mind of the Church moves more slowly than our individual minds.
For now, the Church is still working out the implications of her teachings on faith and morals in the medical and political arenas. Those who insist on a more rigorous application than the Church should recognize that, simply because their position is consistent with Church teaching doesn't mean it is Church teaching, to the exclusion of all other positions.