As a big ISP that stands to profit from the current FCC standpoint, Comcast is in the crosshairs of the internet community.

But if what has been said by all parties is true, I can't find significant fault with Comcast.

Here is the text of the "ad" (typed from viewing the attached image in the OP):

  Get ready, we're increasing Internet speeds in your area.

  Our records show that the modem you currently have connected to our network won't be able to handle these faster speeds, so we recommend updating your equipment.

  <b>Buy from a Retailer</b>

  Before you make your purchase, visit https://mydeviceinfo.xfinity.com to view a list of modems certified to work on our network with your speed tier.

  <b>Lease and XFINITY Modem</b>

  Call 1-855-242-2876 and we will send you a Self Install Kit

  <b>Equipment Update</b>

Seems appropriate and to the point. They tell the customer they can either go buy a modem from a retail store, or lease one from XFINITY. Hardly a high-pressure ad.

Injecting anything into a website makes me feel a bit dirty, but nobody has refuted Comcast's claim that other communication methods were tried first and that this was more of a last resort.

Speaking in general terms because I'm not involved deeply with DOCSIS, older devices are less efficient and generally use more spectrum(even in a cable, there are RF spectrum limitations) to deliver the same speeds. Customers using old devices that don't support the newer and faster standards reduce the total bandwidth available to all customers, increasing costs for both Comcast and its customers.

edit: fix formatting. HN needs a preview button.