Games should always be compared to today's standards. After all, anyone who buys a Virtual Console game is spending money and time on that, whereas they could have instead spent money and time on Darksiders or Heavy Rain or whatever. It would be goofy to say "huh, this game sucks, but I bet it was cool ten years ago. I MUST BE HAVING FUN". Either it's a good game, or it's not.
By today's standards, Ys Book I & II is awesome.
There are people on this very board who never played the Turbo until after the year 2000 and ended up loving Ys. If old games can't possibly live up to "today's standards", then how did that happen? They never played Ys in 1990, so they can't judge it by some mythical "1990 standard". All they know is that the game rules TODAY. And I know it, too.