It's a combination of reforging, faction rep, and infusing. People burned a lot of parts reforging HoW weapons. Many people then decided to dump a bunch of parts into factions, in hopes of getting legendary gear right off the bat. Or, maybe they were a few faction levels from rank 25 for the exotic class item. Then, Bungie dumped this unannounced nerf and now people are panicking. Personally, I've been playing since launch. I'm swimming in about 800 or so parts. Now, people are forced to make reasonable decisions on what to use their resources on. I love it.