There are two key differences: the first is, as other people noted, that they should advertise that range rather than always marketing the highest number. “256KB guaranteed, up to 20Mbs” isn't any harder to sell than telling people they won't always be able drive 65MPH.
The bigger issue, however, is whether those limits are based on the underlying limits of the network or artificial caps: this is currently completely opaque. It'd be much better if they were forced to publish any traffic shaping performed so the consumer can actually make an informed decision. This might lead to other questions such as whether they should be refusing to deploy Netflix OpenConnect nodes which would be healthy – and no doubt a key factor in why they won't talk about it unless forced.
The bigger issue, however, is whether those limits are based on the underlying limits of the network or artificial caps: this is currently completely opaque. It'd be much better if they were forced to publish any traffic shaping performed so the consumer can actually make an informed decision. This might lead to other questions such as whether they should be refusing to deploy Netflix OpenConnect nodes which would be healthy – and no doubt a key factor in why they won't talk about it unless forced.