Where does all this utter nonsense about the speed of links that businesses need come from. An organisation I've done work for (which required me to remote desk top in to their site) with around 100 staff on site was running on a 32Mbps link and it was fine.
For many businesses that need more than that it will be so that the staff can watch Youtube etc. all day!
did these 32 people sit watching full hd and 4k media content?
did they download games in 10s of gigabytes.
did they update their iphones all at the same time over this link?
Generally speaking to reliably supply a service you need a backhaul capable of it. I think jelv you might remember the iphone update slowdown complaints on plusnet's forums before? Or the days when plusnet had to heavily throttle all their customers with the gold, silver, bronze tiers etc. The days before the BT buyout. Yes that what happens when you just roll something out without worrying about the backhaul.
Given aaisp have a policy of not been the bottleneck, I can understand why they wouldnt want to pass over 330mbit customers over a single gigabit link.
Actually I think I misunderstood you, I though you was asking the question why would aaisp need to update that link, but you was rather asking the question why would people need the 330mbit connection in the first place, I think for consumers it the good old ego, for businesses it can very easily be a legit need. But also considering tho its not like you can order a up to 40mbit FTTP service, so for me personally if I could buy a 160mbit FTTP service I Would, even if I didnt need the speed, also in that these services have async up/down speeds, so you might get the 330 service if you want the higher upload speed as well.