Elite members of Hilton HHonors, the hotel chain’s loyalty scheme, have been puzzled for years by its sliding competitiveness. Now the company’s management has stunned them by devaluing the program even more at a time when the industry desperately needs frequent travelers.

Beginning in January, you will need about 25 percent more points on average to book a free night at a Hilton chain hotel, including Conrad, Doubletree and Embassy Suites. That is the combined effect of increased redemption requirements and raised “award” categories of many properties…