These old computer systems are more difficult in a way - you have a big magnetic sheet, you have no idea how the information is even physically stored, let alone what algorithm is used to store it. You don't even know what direction it is to be read in, what is data and what is flags, what encoding method (it predates EBCDIC and ASCII so even if you get the numbers off it, and work out which number actually represent the data - only then are you at the rosetta stone stage). Plus a lot of 50s scientific data was also encrypted on top of that because of the rampant paranoia at the time.
It makes an interesting challenge, tapes are easier as at least you know the direction and that the data is linear.
It is probably not impossible, but the CSIRO has been at it for nearly 10 years and haven't been able to get any data off them.
So there is a valid argument that stuff that is directly human readable/viewable is safer in the long long run as it removes the problem of having to have a device to read the data as you have it built in.
Of course the upside with digital is you can make a perfect copy, and if dilligent transfer it to newer media as it comes along, like the X0 project transferring laserdisc onto DVD - from that point onwards it could be pushed onto tape, HD-DVD, holographic storage etc. But if that wasn't done, would there be any laserdisc players still operating in 300 years time? If a digital file is released into the public domain then it is likely to still be around after a long period of time and if a digital copy of a digital original will be the same as the day it was struck. This is the first time in history that such a thing is possible.
Film has its own problems, countless important films have been lost completely (or partially) due to lack of interest by the studios themselves, it is easily damaged and degrades over time.
Last century Disney re-used most of their cels so the original artwork was literally washed away.
Lucas has supposedly cut up his original negs, making the OT non existent in its original theatrical form as far as a complete negative goes.
Companies cannot be counted on to maintain archives, the moment they lose commercial interest in a work, it is likely to be dumped.