There is regular discussion among Mormon bloggers about the term "cafeteria Mormons" - those who pick and choose what they will and will not accept - who fill their plates with what they like to eat. I generally hate those discussions, since they nearly always are directed at judging what others choose to eat - labeling others as different and highlighting those differences.
Ultimately, the only one who can tell what foods we individually are capable of digesting properly is the Lord - the one who paid to become our judge and is uniquely qualified to be our chef. We often are not truly aware of our own limitations and biases and blinders and other obstacles, much less those that others carry within them. Therefore, we can’t judge with 100% clarity whether or not someone else is living the Gospel to the best of his or her ability. Hence, "Judge not, that ye be not judged."
Given that situation, why do I care what anyone else in the cafeteria is eating? I can think of three obvious reasons without much effort.
First, if I believe they are eating poison, I will warn them of my concern. Second, if I think they are going to get sick from over-indulgence or starvation, I probably will warn them of that possibility. Third, if I think what they are eating tastes terrible, I might warn them. Everything I do is intended to help them experience the delicious food that I have tasted. Once, however, I step over to them, take away their food or put my own on their plate, insisting that they eat exactly what I’m eating or get out of the cafeteria - at that moment I have crossed the fine line and done to them what I would never dream of allowing someone to do to me.
I like the idea that all of us are cafeteria Mormons, as to doctrinal acceptance and/or practical application, because that concept allows us to quit labeling each other and quit trying to determine someone else’s level of righteousness or worthiness. As long as someone is willing to endure to the end at my side, it’s not my job to categorize their faithfulness but simply to walk along and enjoy the companionship of the journey. Who cares if there is a scent of smoke or the reek of alcohol or no payment of tithing in our chapels - ad infinitum? The temple is one thing; the fellowship of the Saints is another thing entirely. Given what I have seen in my callings, I am convinced that if all of us stopped labeling each other there would be more converts flocking to the Church and fewer members drifting into inactivity - and the Church would be an even richer and more vibrant community than it already is.
Summary: If someone continues to attend church whose plate looks radically different than mine, and if that person does not heed my warnings if I feel prompted to give them, and if that person is not trying to force others to eat exactly what he is eating, then I shut up and enjoy the company - and usually end up acquiring an appreciation for a food or flavoring I had not known previously.