I think when people start exploring, residential explores are an easy win for dipping your toe in the water and getting out there. The majority aren't belled up, are walk-in's, have a lack of security and are generally, hassle free. To be fair, after doing a few and seeing what others are doing non-residential wise, if people stick around most tend to move on to non residential stuff in the end.
It is probably in the last few years that they are more noticeable because of Goontube and Facebook (time chamber, untouched for years, yada, yada, yada) and seem to be accepted on GT and FB as legitimate urban exploring.
Personally, I don't like them and wouldn't do them simply because after having my parents house for nearly 20 years (in another country and not 10 mins down the road) before selling it, I know what a worry it can be when you can only visit / use it once or twice a month - is it secure, is it going to be broken into, will the pipes burst in winter and fuck over the place, does the garden look unkept to make it look like nobody is living there, etc.
And I know the last thing I would want to see was a gang of twats rifling through personal property and memories to get likes or to get people to 'smash the subscribe' button.
Each to the their own though as people are still going to do them but can fully understand the shite that Admin and the Mods get from them.