When looking at the pool rewards and the fact that it comes from a somewhat 'trusted' exchange it is no surprise that Binance catches a lot of new comers that want to get on mining.
Pool rewards are the same across all pools that pay in the method, PPS+ for the case of Binance, I think the most important factor after the one you listed above was the fact that they offered 0% fees mining for 3 whole months, nobody can do that shit to be honest. PPS fees have to be high (the explanation is a bit too long but that's how it is), so when Binance offered 0% fees when pools like Viabtc was 4%, a ton of miners moved there, and after the 3-month free period, Binance didn't come back with a 3% or 4%, they came back with 2% which is the lowest PPS+ fee you can find in the market, at that time I think only f2pool was offering a similar fee, so Binance managed to keep most of the miners who came for the 0% fees.
On a side but related note, being a bit too picky, I did not like Binance pool at all, I might not have given it a fair test and it must have improved since I tested it in its early days, but it was far from stable, however, seeing miners still use it, they have probably improved a lot compared to when they started, I still don't use their pool service since I use their exchange, it's a bit too risky to be all in one place, which is funny because most miners who use Binance will tell you they do so because they can withdraw to the exchange for free.
and likely contributing to the pool growth. Their rewards are also convincing. 
