As long as they can rely on a nest of less than objective judges eager to serve troll interests, they don't have to worry about fee awards. The decision left a lot of power to the discretion of district judges so a single predictably biased district can corrupt the whole national system.
The Rep. Goodlatte bill that was passed by the house would make fee awards routine and then East Texas judges would have to justify not awarding fees. That would be a much better reform.
The Leahy senate bill will probably be a very tiny change in the existing language because Leahy's trial lawyer supporters don't want to loser pays principle to gain a foothold. Leahy -- and most trial lawyers -- have said that patent cases are an exception the the general principle, but they aren't ready to let any wholesale reform happen on this point. Usually trial lawyers argue that loser pays disadvantages vulnerable victims; most federal civil plaintiffs are much poorer and smaller than defendants. In patent cases, the opposite is true; patents are the tools of trolls and big companies to extort and destroy innovative small businesses. Most patent cases are brought by established wealthy troll agglomerators against companies that could not conceivably afford a full trial.
See here for how biased cases are to E Texas already: http://patentlyo.com/patent/2014/04/district-courts-patent.h...