They're not necessarily a bad idea, even though they'll have no impact at the destination. It's the journey
With a warp drive, people from Earth could routinely venture to the millenia ship and take tours of it, staring at the spooky frozen embryos or aging crew, still stuck in the world of 2100 like cavemen stuck on a raft going in circles in an eddy in the Pacific.
In inflation adjusted constant 2010 dollars, I'm thinking $350 for the flight out to the millenia ship and $50 for admission. The souvernier shop would make a killing and could easily be restocked from the warp ships. Of course the actual crew would quickly abandon the effort, so you'd have to pay college kids to dress up in crazy year-2100 costumes and speechify in the old way, but they work cheap. Since the journey is going to take thousands of years, the return on investment should be astronomical.
After the first thousand years of profitable business you'd even hire people to play tourists from earlier centuries, so new visitors could see what it was like to gawk at the "Twenty-One Hundreders" back in 2350.