There's a third option in there that they actually are making franchise mode better but the additions haven't been what you wanted to see.
Many of the major additions and changes over the past few years - Things To Do, Play The Moments, rebuilt Scouting, Weekly Training, Play Now Live, etc. etc. - each focus more on newer Madden players than experienced ones. These features absolutely were built where they did not exist before, and they each made Franchise a better experience. It can also be true that these things aren't what a community like this one wants to see in the game.
My point is that Tiburon neither making up numbers nor are they lying to you just to make you quiet down.
This is an uninformed and agenda-driven assumption. From an engineering perspective, MUT has little to zero day-to-day impact on Franchise.
Compared to Franchise, MUT requires very little engineering support (especially post-launch) as it was built as a content-driven mode from the get-go. A great deal of the work on MUT is in daily and weekly content drops; that is, designers (not engineers) regularly building and delivering new cards to collect, new sets to complete, new packs to buy, new daily and weekly challenges to play, new promotional events in which to participate, etc. etc. Unlike new features in Franchise, these content refreshes don't require building new screens, adding to or extending databases, building new network requests and callbacks, or any other significant engineering tasks. It's just data packaged together with various internal tools delivered into a game client and server which already knows how to handle that data.
By comparison, if you want to get some cool new feature into online Franchise, you've got to go through all the traditional engineering rigamarole. It's a much bigger and a much different type of effort than that which is needed to drive MUT.