Guy Pearce as opposed to older actor as Weyland. Please no spoilers.

Now that the film is released any thoughts on why Guy Pearce was slathered with prosthetics to make him appear old as opposed to having an older actor, of which there is a plethora that range from great to masters, play the part of old man weyland? I'm asking because it seems like his appearance seems to be kind of odd, listening to some fans and reviewers. Since it seems the movie focuses on his older days it would seem that they could get someone who is younger and known or unkown to play the younger version if needed at Ted Talks, etc. I have not seen the movie yet and after viewing might love the performance or realize that he will be back and explored as a major character in his younger days in Prometheus sequels (prequels) . Or he might indeed have found the fountain of youth he is seeking, ergo the prosthetics. As stated earlier, I don't want to know his fate, just thoughts on if his character will be revisited, or if Ridley just chose him based on his talent and acting abilities.