Unfortunately, it's an endemic problem to a community like this, I've found, with no real solution. The thing is that nothing encourages any kind of accountability with duly informing someone of a dropped RP, nor is there anything to discourage a lack of accountability. Sad fact is the majority of RPers will drop RPs without a word, often simply because they're bored, and won't say so (and in some cases, don't feel obligated to answer querying PMs from someone wondering why they're dropped). It's more a laziness/no incentive issue (but you can at least check if it was a likely IRL issue--if a partner goes silent in your RP, but is still active and picks up new ones, yeah, they kinda suck. But if someone vanishes off the face of the forum and doesn't log in, or doesn't respond to -any- RPs, it's more than likely something IRL got in the way and not their fault, or they can't work up the mental energy to post).
Really, there's not much you or anyone can do except personally blacklist such people (not that they're ever likely to RP with you again anyway) and move on and try and find someone else.
One thing I do note from your RPs is that you seem to do short/bullet-post RPs. -Generally- speaking (not an absolute truth), it seems to me people engaged in bullet-post RPs tend to be flighty and drop things as quickly as they pick them up. My reccommendation would be to stop posting with your cell phone and only post on a real computer, and find RPers who write longer posts at a slower pace. Sometimes, people willing to do that stay engaged longer.