I feel like what you are describing are the faddish/scammy types of apps that people attempt to make a quick buck on and not the great indie apps by a small team. Great apps will be found and bubble to the top. Bad apps that are trying to make a quick buck by just being popular are always going to be fighting an uphill battle.
Despite my best efforts and what I thought seemed like decent rankings, I ultimate had to chalk it up as a failed business. You could argue the quality of my app was not there, but I definitely poured what I could into it with entirely honest intentions.
Unless you have something really special, it's hard out there. The more niche your product, the harder it becomes to get noticed amongst the cruft.
Google Play has been a waste for me. I even launched a free ad-supported version of the same app there and it gets less downloads a day than I sell on iOS or Nook. Yes - more people buy the same app on Nook than download it for free from Google Play. That shows how broken discovery is on Google Play. Well that and how small the Nook store inventory is.