It appears that there's an easy way around this. The lease states that the storage space is furnished "under a revocable license." The board should say that all licenses will be revoked unless the lease is amended to allow the coop to charge for use of storage space. This should be done in a straightforward, common-sense manner: "Given our ever-rising costs and the high premium on storage space in New York City, the coop cannot afford to offer this amenity at no charge. We must either charge for storage space - which will require a supermajority vote of shareholders to amend the Proprietary Lease - or we must convert the area presently used for storage to another use." Done properly, this should ruffle no feathers except those of the people who thought they'd found a sly trick to get free storage lockers forever.

As for bike storage, the same "amend it or lose it" approach would work, but bicycle storage is less space-intensive. In our building, we charge for lockers but offer free bike storage since much less space is involved per person. We're not stuck with a "furnished gratuitously" clause so that works fine for us.