Why is Teambuilder Team only for online?

I just bought the game on sale a few weeks ago so that I could create my team and play with them on Dynasty mode only to find out you can only do it online and not offline. I thought the reason was because the game pulls the data from Teambuilder online, but that is not the case. After I already started my Dynasty online with my team, I made some uniform changes in Teambuilder and published it. However, none of the changes I made affected my current online Dynasty. So what is the purpose of forcing us to only use our created team in online mode? It makes no sense at all.