Because as with every political issue, the definition has been twisted by the well-advertised incumbents to transmute grassroots concern for change into status quo preservation.
The actual issue is broad and vague patents on obvious things, where the novelty is confined to their obfuscated wording.
Techniques that are commonly independently reinvented should not fall under the patent system at all. But then some lawler figures out how to make a tenuous connection with a completely lineage-unrelated patent and they go trolling for settlements, regardless of whether they're a small company that does only this or staff counsel for a large company that also happens to manufacture things.
But no shit large companies like IBM, Apple, Oracle, etc want to limit patent reform to "non-practicing entities" and continue their general low-stakes protection racket while screwing over the little guys (genuine patent holders and patent victims alike).