Hextech Gunblade has been nerfed, but remains one of the strongest items in the game for Hybrid or even most AD based champions, due to the spell vamp, great all around stats and the active, which can be huge if used properly.
Riot generally wants to stay away from having a lot of stats on any item, because it makes any 6-item build stronger, and there has to be a limit to how strong/effective any given champion can get. Buffing or Nerfing Gunblade's stats, not price, affects the end-game strength of any champion that can use it effectively, but primarily hybrids.
One of the main reasons Gunblade got nerfed -> Its spell vamp got turned to unique passive because Akali Jax and Katarina were just way to freaking strong just by stacking gunblades, among other champions. Gunblades are now less effective when stacked. Riot also wants to reduce the effectiveness any items that make any champion too strong when they just stack one item in particular, and Gunblade was one of those items that could be stacked with great success.