Yeah, but yours is a minority opinion - you don't matter at all.
Exactly. Let's face it, people buying a High Definition version of TNG probably aren't going to care if the SD version is included. Having invested money in an HD set-up, why would you bother? Maybe some purists will, but again, no one is forcing you to buy them. Your existing DVDs will function adequately for the foreseeable future, as Blu-ray players are backwards compatible. You have had ample opportunity to buy the DVDs, and even if they go out of print, there will be plenty on eBay. If you are that much of a purist, you will already own the DVDs.
The bottom line is that Paramount (or whoever) are under no compulsion to include the old versions on an HD release, and I'll be surprised if they do. If they do, then fine, everyone's a winner, and this whole argument is pointless. On the other hand, the fact that there may never be a TNG-R is more likely to render this entire thread pointless. But it's fun to argue.