It's a shame that he was only 40 years old when he died and that his career was curtailed when he was still so young.
A very unfortunate age and circumstance for his death. The in ring career being shortened hurts a bit alone at that. Despite his rather short run in a more memorable light, he put out a handful of gems in almost anywhere he wrestled. A few of his matches in Japan, and WCW can really reveal how talented and sharpened he was in his craft.
He was actually a really good tag team wrestler. If you dig around a little bit you can find a lot of his work with a tag partner or two and he really shines through a mist of others and their move sets. His character and ability to tell a basic story in a compelling way could really polish a match.
Also, he had various great matches in NJPW and All Japan Pro Wrestling through WCW connections. The 1992, G1 Climax had him face off against Masahiro Chono in a really methodical classic styled match. Rude really showed the potential of his in ring work, and mat based skill here. If you get a chance I'd reccomend watching it. Another good one is Rude, Terry Gordy, Steve Williams vs Misawa, Kawada, and Kikuchi in AJPW 1991.
He won championship belts, and had moments worth more than a note. If you really go back and dig into his career I think most of anyone can grow an appreciation for him not only as a performer, but as a person. You mentioned what Bret had said, and it apparently was more than true. Multiple people have had nothing to say but good and more good about Rude.
An in ring career, and life ended short leaving his career to be overshadowed by his ever growing peers. To deem his career underrated is hardly a worthwhile statement. He was great on the mic and worked his character well. He had feuds right out the gate with big and notable names. A great worker and a great friend to many of our favorite stars in Pro wrestling. Championships have been won, Great matches have been held. I'd say it's safe to grant him into the Hall of Fame. This time around certainly seems right.