Wouldnt it be awesome if Fromsoftware would take all their older IPs which they are sitting on and make a compilation with it?

Kingsfield series, Shadow Tower series, Kuon, Otogi series, Lost Kingdom series, Armored Core series, Ninja Blade and the list goes on. They have made so many games over the years who they are sitting on. 

A compilation for 50 bucks could sell pretty well and i doubt most of these games would sell well for 10 bucks each on its own. I think people would be corious about fromsoftware and it would help them to get more marketing for their upcoming games like Dark Souls 3.

I'd love an Armored Core Replay.

I'd buy it just for King's Field. I loved that game!! (Well, it's actually the second one, but the original was not released in the West).

Include Evergrace and Forever Kingdom in it too!

I've been gaming since like, 1982ish and I haven't heard of one single game mentioned in the OP so, no... it would probably be a commercial disaster.

I played most of their games at release, they were one of my favorite niche companies sincce back then, and AgeTec was synonomous with them as they localized almost everything they developed. 

The only reason that most people know of them though is the surge in popularity of the company because of the Souls series.  I think most people would buy the game and be disappointed though, it's not like the Souls games are mainstream, and these games are even less so.  They're great, but they're more to the niche audience.  

I would like to see a PS4 exclusive King's Field with the graphics enhancements they could push out now though and hope it's not just a first person Souls game. 

Nobody cares about their non-Souls/BB games.

That's very assuming of you considering they have a lot of older games such as the ones the op listed. 

Otogi 1 and 2 on the original Xbox were awesome games. 

You sound like a somewhat bitter or jealous Nintendo fan that didn't get to enjoy their games. 

Sorry if I'm wrong but that's how your comment sounded. 

This isn't a question of quality, but commercial viability. Such a collection would barely sell as most people have never heard about these games. Rare replay actually has famous classics in it...

Famous or not, Rare Replay isn't selling well either.  It was already put on sale by Best Buy and Amazon for $20 earlier.