I'm a full-time STR-er so I have a guest perspective on this. While there is risk for a host there is always risk for a guest when renting a place too. You read as much as you can about the listing, read all the reviews but nothing puts your mind at ease then seeing the actual property. Does it match what was advertised? Are there things missing or that you need to pick up? There are amazing STRs out there with stellar hosts then there are places with lots of reviews, fabulous photos and a disappointing place. Furnishings vary so much and yes they are listed but don't always match listing. Personally, I like to know these things so I can get settled. As a host you may feel secure and comfortable with your property but this is most like your guests first time there. For a lot of guests vacations do start when you "arrive" and sometimes it is hard to get into that relax-have-fun mindset when one of your biggest factors of the vacation (housing) is still an unknown. It is a similar mindset to wanting to check into your hotel before doing your activities. To "get it out of the way".
I often ask for an early check-in (if I need one) and appreciate when it can be accommodated but understand if it is not possible. I get the time between turnovers. If they can accommodate I always consider it when doing their review as them going above and beyond. If they charge for it I don't consider it a perk at all since I paid for it, especially if I see their calendar was free the day before.
On the flip side hosts ALWAYS ask when I'll be checking out even though there is a clear check-out time. This is obvious why but how is this scenario any different than a guest asking to check-in early? There are always multiple views to every scenario.
