I'm losing 1 - 2 pounds a week. Every bit of loss is encouraging. With that kind of weight loss, the difference between losing .6 pounds in a week and losing 1.4 is significant and I'd like to see it. Obviously, some people feel that seeing that kind of detail is helpful rather than crazy making. If GSK permitted weigh-ins using ounces or tenths of pounds, people who felt that it was helpful could use the feature. People who didn't have scales with that kind of detail or who found it unhelpful would be free to continue rounding.
Despite GSK's advice, different systems work for different people. I weigh myself every day because, on balance, I find it helpful. I do it first thing in the morning, after I've been to the bathroom and wearing the exact same thing, thus, as much as possible, comparing apples to apples. I know if I've had something the night before that makes me retain water and I weigh 2 lbs. more than I did the previous day, it's only water weight and I don't worry about it. Seeing those tiny, incremental tenth of a pound losses day to day is motivating and encouraging for me. I'm sure I'm not the only one, just as I'm sure there are plenty of people who are only made crazy by getting on the scale every day.
Where people differ on what's helpful and where so many people have made it so clear that they would like to be able to check in using smaller units, why not provide the flexibility?