Eliminating patent trolls would eliminate that problem for large corporations, although it would still cost them million of dollars to apply for patents solely to cancel out others' patents through cross-licensing. Start ups are even more screwed because all of the large incumbents still each have a huge arsenal of broad software patents and can bury any software start up in litigation who tries to compete with them. This also makes having a software patent essentially useless for a start up because any attempt to assert it against an incumbent would only result in counterclaims and ruinous litigation costs. The idea that a small practicing entity can realistically assert a software patent against a large tech corporation is beyond belief. And that's before you even consider the six-figure cost of paying lawyers to get a patent through the patent office, which then generally isn't even issued until the technology at issue is either obsolete and disused or so common and ingrained in the status quo that issuing an effectively retroactive patent on it without prior notice to those who have since adopted it is inherently unreasonable.
Software patents are fundamentally useless and should be abolished.