Hello!
Astrology is a truly real science that can describes somebody. We know this, but what if one develops herself?
For example, I don't have anything of Aries in my natal chart, but just some time ago (like three years) I was starting to being very strong, very energetic, and nowadays I still being similar and I'm constantly improving.
HAIL ZEUS!
The point of meditation is to change you in the best version of yourself. You will still be yourself but better and without flaws.
The thing you should remember is that aspects, houses and so on point to features of your life and personality, like whether or not you're weak or strong enough in the first place to actually survive, then to the actual nature of your relationship with the world around you (you may of been born in a bad or good environment and so on)
With regards to "personal development" this actually goes hand in hand with astrology, but it is not wholly dependent on houses and things like that, astrology only shows you the nature of how to speed up your personal development. You can then utilise this in the physical actions you take to develop yourself, to do it faster.
There is no "astrology vs personal development" your personal development in physical strength is your Mars, development in intelligence is Mercury etc. Everyone has strength and intelligence, but whether or not they work on it can only be guessed by a chart, they still have free will.
When you are aware of your strengths and weaknesses, you still have to work, and you can work on whatever you please- but to know of these things aids anyone, Astrology as a whole will basically bankrupt all the cheapskate psychologists and "get-rich quick" people when it comes to light.
Saytan Abbrasa