No, because as the seasons in your franchise progress, what happens in it really begins to diverge from what happens in the NFL. One great Franchise mode would keep me busy for a year max, because not even the most dedicated Franchise player can keep up with all the roster changes, coaching changes, uniform changes, etc.
NOT TO MENTION the annual feature updates.
If I may, I believe the only real reason the Franchise mode has been lacking is because the limited resources of the development team were spent elsewhere. With Head Coach guys on staff now, I would expect to see some nice upgrades in Franchise mode.
And since when has a great product LOWERED the chances that a customer buys the NEXT product from the same people?
If anything, a greatly improved franchise mode will solidify and add a lot of consumer loyalty. Consumer loyalty is the wild card factor in supply and demand that every supplier would like to have on their side. Consumer loyalty = profit.