The answer is:
IPhone (or actually any other smartphone who has multiple models)
When you use me, you only ever see what I have become instead of what I really am.
If you use a smart phone you see many things, often a small gaming device but it used to be and is in essence a phone
I can be used to do powerful things, but I can be very fragile at my core.
you can do powerful calculation with a smartphone, as a matter of fact it is more powerful than the computers NASA used to send the Apollo missions. A smartphone (just like a computer) uses CPU cores.
Through time, I have changed lives!
A smartphone (or normal phone) saved lives (calling emergency services) and it changed many because everything became easier.
Unfortunately some choose to hate me, and others choose to embrace me.
Many people hate Iphones, some love them. but in a broader sense some people find mobile phones (smartphones) are ruining people's socials skills, others accept it.
I am used around the world in many different ways.
well a smartphone has many different applications.
My family is huge, and yet still getting bigger.
iPhone 3G, 3GS, 4, 4S, 5, 5S, 6 are all part of the family.
It is important not to forget about my elders, as they still needed (by some).
People still use older iPhones (with different sizes and older iOS versions), so app developers need to keep that in mind.
I would like to thank Pacoverflow for his additions for the last 2 sentences.
As for the hint:
if you have siri you can look at your phone but you do not have to touch it to use it, you talk to it. <- ye this one doesn't fit 100% xD
An other answer:
a woman. bear with me here.
When you use me, you only ever see what I have become instead of what I really am.
Haha use :P well if you 'use' a woman she becomes an object instead of the person she really is.
I can be used to do powerful things, but I can be very fragile at my core.
Woman (love) are a power to be reckoned with but at their core woman are fragile and precious.
Through time, I have changed lives!
every great man (in history) has had a woman supporting him, isn't that how it goes? A woman can often change a man's live.
Unfortunately some choose to hate me, and others choose to embrace me.
Some hate woman (many women hate other women), some hat them because of their beliefs (in the bible a woman was tempted to take the forbidden fruit). Do i even need to explain the embrace part? ;) if you know what i mean.
I am used around the world in many different ways.
women are very versatile, they are used as babysitter, businesswoman, teacher (etc)
My family is huge, and yet still getting bigger.
well obviously any person's family is big, we're descendants of millions and still continue to grow (childbirth)
It is important not to forget about my elders, as they still needed (by some).
parents are the reason we are all here, they are also still needed for love and attention. (also to watch over the grand kids).
As for the hint:
you can look at other woman (which you are not married/engaged/in a relation ship with) but you can most definitely not touch