I love my 1974 Raleigh Pro. It is a bike I can sit on for four days and nights and still love it. But basically the only relationship between the Raleighs from then and tho new ones is the name. The brand has changed hands a couple of times and today is fairly interchangeable with lots of other Taiwan-built bikes in similar price ranges, often capitalizing on the reputation of an older brand name.
But that said, those Taiwanese factories really do know what they are doing when it comes to building bikes. They aren't going to be cutting edge like the latest Trek Wunderbike, but for basically good, solid, standard technology in the middle of the road price range, they are no different and probably a bit better value than something equivalent from the bi name brands. So maybe the technology is five or ten years behind whatever won the TdF this year, but we're talking bicycles here, not smartphones, and most of us are not buying the real cutting edge anyway.
We like to scoff at "cheap Chinese knockoffs" but the bike factories in Taiwan make good stuff to a high standard of consistency (within the still-applicable rule that you get what you pay for). Even though a new Raleigh isn't from the same company as an old Raleigh, it's still a good bike for the price, and so yeah, it probably is under valued WRT its brand image.