I don't buy for one second that Ricketts is the driving force behind not signing a 10 year deal. Ricketts is a business man. He of all people understands investments. There is no chance he believes that signing one of these guys to a 10 year deal is a bad investment. If you look at all of the mega contracts in history and compare it to what teams are paying on a per WAR basis, there is only 1 that comes out as a surplus off the top of my head and that's Max Scherzers deal with the Nationals. Yet with all of the evidence to suggest that no matter how good the player is, they aren't worth the money, then why do teams continue to pay them more and more? Because to the owners it doesn't matter how they perform on the field. What matters is how much revenue they bring in and they all understand that someone like Ohtani is going to bring in his entire contract in revenue by like year 3.
On the other hand, Hoyer's job is on the line with these decisions. If Ricketts is willing to sign off on 6-7 years at $35M/year, then there is not shot that he wouldn't sign off on 10 years at $30M. Because a dollar today is worth more than a dollar a tomorrow. So while Ricketts would sign off on something because in the end his bank account will grow no matter what, Hoyer has to keep producing to keep his job.