Why I hotel hop:
All stays/nights are on my dime so it's cheaper to hop for 25 stays than book 50 nights.
I maintain top status with Hyatt and Starwood. I now have LT Plat with Marriott so that's my backup if Hyatt/Starwood are too expensive.
My employer pays for my hotel rooms but I don't get credit for them. However, I do get status recognition so keeping top status is well worth it for me.

I just did 4 nights in NYC with my daughter on my dime. We hotel hopped every night. First night was Hyatt/SPG; the other 3 nights were all SPG with me booking (and getting credit for) 2 rooms in each SPG property. All of the hotels were near each other so it didn't take too long to hotel hop.

I can either hotel hop a bit or go on more vacations. Since I have only x number of days for vacation, I hotel hop.

I also live in Las Vegas so I can pick up a few super cheap stay/night credits with Mlife.