There are actually places that have older style drives to be able to recover data from those tapes sitting out at places like iron mountain at the moment. Of course, one issue here is that to recover data from 10 years ago - or more but it goes a lot further than just the tape drives.
so, once we've found the tape drive that we need we'd then need to find the tape(s) and hope they work.. hang on, how do we restore it? Ok, we need to build a server so we need the correct software - maybe even the patch version. Where do we get that? The supplier doesn't exist any more (or has been bought out). We've got the server backed up on tape but are now in a chicken and egg situation and even if we get the server back we may well need the domain as some backup products (netbackup for example) will use the domain SID to generate an encryption key.
You did keep the passwords for the domain somewhere safe didn't you and not just on the tape????
Long term archive presents a whole series of problems. Tape format and machines to read it are just one of those problems.