Lower-quality is what has happened. They have seen everyone jumping on the less effective steel piping for cheap $$ and want some of the action. Their original aluminum pipes are the best, but they have seen that most people don't know the specifics qualities of the materials used and buy whatever is cheapest. The stock plastic pipes lose less heat than steel pipes do, weigh less, and the only downside is they are fragile and prone to leaking at high pressure. Aluminum intake piping will always yeild the best results (there are types of plastics that have the strength and specific heat to be superior, but none of us can afford it lol). You also don't need a tig welder for steel. I actually hate to see people building s*** parts for cheap because it shows the vendors that MSP owners (majority) won't pay for quality parts and scares them away from making them. There are 6 shops that could make me mild steel IC piping (and I live in a small Idaho area) locally, but none that could make (mandrel bends) and tig weld together aluminum.