I actually HAVE done this on several occasions as although I do not like bus trips (see earlier question), these are just an hour or two or three, and it gives you an idea of where you are so to speak.
From that we could sometimes decide where we wanted to go and on some of them you can hop on and off during the journey as we did in London and New York.
Here is Perth you can also do the same, so assume you can do this in most major capital cities.
When I first arrived in Townsville over 30 years ago, I did not know a single soul, and as there vwas a lot of history to this city, I decided to learn more about it. These half day tours are great for this kind of thing, and the one I went on included a lovely tropical morning tea! Between that tour and walking a lot, which I enjoy so much, I had a fabulous introduction to my new home!
Yes we often do this. In cities where we are not driving, it is a great way to get a good overview and help orientate ourselves. Once I would never have done this, but after an extremely informative walking tour of Singapore, I realise how educational and informative they are. A bus tour is also a good way to rest weary feet for a while. The hop on hop off busses are worth investing in too as they usually travel to the tourist destinations. On more than one occasion we have mentioned ,in conservation, an interesting fact that they were surprised we knew and they didn't.
That doesn't sound quite right. In conversation with friends who are local, we have surprised them with local stories they didn't know. Our friends were so intrigued they decided to do the tour and get to know their own town better.