There are times for every machine. The Browning Hi Power came along as a military weapon, but didn't have the American provenance of the 1911. The 9mm wasn't considered a man stopper, like the .45 ACP. After WWII, it was fairly easy to obtain surplus 1911's. Not so with Hi Powers.
There were also huge amounts of surplus .45 ACP ammunition. Not so with 9mm.
The 1911 is very simple in design, and it lends itself to modifications that vastly improve the original design. There isn't a single component in the gun which hasn't been improved, and updated. Not so with the Hi Power.
The Hi Power has always been seen as a "European" gun. It has never had the market penetration of the 1911. Browning Firearms never had enough volume to overcome Colt in the handgun business.
I've shot a number of Hi Powers, and I own two in .40 S&W. I love the design, and for a "double stack" design, it fits my hand far better than Beretta, Sig, or others.
However, I can readily understand Browning's desire to let the Hi Power die. With all the other 9mm pistols out there, the Hi Power just doesn't have the "legs" to compete with them.
The Hi Power is going to be one of those designs, like the original Winchester Model 70, and the Colt Woodsman. It will be nostalgic, but for the most part, impractical.