Most people don't know how to reverse image search - this is primarily a travel site, and there's no reason to penalise travellers who don't have above average tech-savvy. Also, ideally speaking, we'd hope that many ID-this questions should be either a photo the person or someone they know took themselves (in which case reverse-ID is likely useless), or a link to a travel site or similar where they found it (in which case hopefully that travel site didn't just steal the photo and hopefully reverse-search is useless, but, well, you know... and also like in that example when an image is widely stolen it's often also widely mis-captioned).
So let's not punish people if they don't know about a tech tool that might not even be appropriate to use in many cases. I'd upvote a question that includes "I tried reverse image search and found [x]" though, like this one. Downvote if it's seriously lazy like "Where's this" and there isn't even any clue where the image came from.
If, in, future Travel.SE gets many, many such questions a day and dealing with them all every day becomes a real problem, you could do what some sites do (e.g. Graphic Design for font-id and I think Movies for film-id) and have a strict, rigid policy. But it's worth stressing that these are extreme, obtrusive solutions to a real problem we absolutely do not have right now, where for a period of many months 25%-50% of new questions on those sites were poor quality ID questions:
- Fixed requirements for what people must do to ask a question. For example on Graphic Design they must try an automatic font-id tool and report on what it said, on Movies they must give a few mandatory details like when and where they saw it
- When someone asks a question and adds that tag, a nagging popup appears telling them briefly what these requirements are, linking to more detail
- They have an agreed precedent on meta that if someone misses this notice and asks a question without meeting the criteria, the question is closed and they get a comment linking to the rules, then is re-opened when they update it.
We don't have any equivalent problem right now - we get maybe 1-2 ID questions a week and they're usually interesting and popular, unlike "What's the font in this document?" // "It's Arial..." (which was funny the first time...) or ridiculously generic movie ID questions. We don't need to take any extreme measures, but the option's there if a problem emerges in future.
Let's not force users to jump through hoops for a relatively rare, usually popular type of question where, in the ideal scenario ("I took a photo of this, what was it?"), jumping through that hoop will be a waste of time.