Really not sure where anyone gets the idea that 6+ gigs of data usage on an UNLIMITED data plan is excessive.
But what about those who push through 200+ GB of data usage on their unlimited data plan on a monthly basis, just because they can? Do you then consider that excessive?
Obviously, it is a little of both (well, mostly a decision by Verizon to soak their customers for more money). With video streaming, cloud storage, etc., people have and will obviously use more and more data over time. Back when I got my very first smartphone, a Blackberry Pearl, I used the phone solely for email. With the efficient Blackberry compression, I averaged between 8-10 MB per month. A year later, I replaced that with the Blackberry Curve. My data usage slowly crept up over time and I was averaging about 25-30 MB per month. Then came the Blackberry Storm. Data usage then averages about 75 MB per month. Then the world changed with the introduction of the Motorola Droid. My data usage spiked up to around 150-175 MB per month. As the OG Droid then got replaced with the HTC Thunderbolt and LTE became available, my data usage doubled to average around 350 MB per month. That got replaced by the Rezound and now replaced by the Galaxy Note 2. I don't do video streaming (no Netflix, no Youtube), but I do check email, have pictures taken with the camera automatically uploaded to Google+, sync Facebook, have a weather widget, etc. I now average about 1.30-1.5 GB per month. I don't tether, and while I could, I very rarely connect the phone to WiFi at home.
With our 5 smartphone lines, combined we use about 11 GB per month. We are the customers that Verizon is really targeting the data share and metered data plans towards. We are right at the cusp of reaching the "limit", so while it may be tempting to switch because it may cost the same now, in the long run it will cost us more.