Personally I like to know the weight per square yard, but there are very few websites that tell you that info...perhaps because it is not available to them. Thread count by itself means nothing to me and certainly does not mean better or worse, softer or rougher, by a long shot.
When I order online, knowing the weight, the heft of a fabric if you will, is as close as I can come to feeling it and now that the manufacturers are making that more of a variable, it is more important, to me anyway, to have that information available before I buy 'sight unseen'.
How hard would it be for a retailer to weigh a yard of each fabric on a food or postage scale before, or after, they cut it into fat quarters? It just seems like the most objective way to describe weights.