Perhaps hostel review sites could have check boxes for traveler reviews, one of which would be "locker?"
I'm presuming you'd believe several reviewers marking such boxes. So . . . email the review sites and suggest such a thing to them?
BTW can you put yourself in the position of hostel owners and imagine what problems they may face if they allow private padlocks to be used on lockers? I don't know of any, but hell, maybe there are local regulations against it. Might be a good discussion question to ask owners now and then. Hmmm, maybe the police demand it so drug searches are easier. Shrug.
Booking sites, review site, companies like Tripadvisor are not wanting to address the essential security problems of the naive travelers. Reviews are for the most part only to point the good, not to address real problems.
Theft by cleaning ladies in 5 star hotels is 20 times worst than in Hostels. Yet, the average person refuses to admit they are robbed, they see it was an admission of of their stupidity. They think,
"I was given a security box, and I did not use it, so I was stupid."
Many people get robbed on vacations, the reason why people do not travel more than a couple weeks per year is because it is uncomfortable. The biggest is their subconscious knowledge they are open to theft, dangers. I live in security, with the knowledge that I am safe because i have systems, methods, protocols that make me the least opportunity target for problems. There are some very soft targets out there, who have no system.
I am now selling a Travel Security Training Kit, I called it training, so that hopefully buyers keep their brain working, and realize to stay safe is a process, not just talk.
Adapting to dangers is how the survival of the fittest concept works, this is Darwinian.
If a person is not trying to adapt, they are the losers in the game of life, to think out of the box is needed to win.
"the reason why people do not travel more than a couple weeks per year is because it is uncomfortable."
haha Well, let's not go overboard. For Americans, the reasons they don't travel more than a couple weeks per year is that's all the vacation time their job grants. Discomfort isn't even considered when thinking of vacation. Vacation days permitted are.
I believe everyone is responsible for their own lives, and they do what they want to do, and blaming others is the excuse. Traveling the world is cheaper than living in the USA.