Brazilian dude wrote:...Gavin likes getting up early because it's so quiet.
Pete likes to get up early so he can get to work before the rush hour starts.
Who enjoys getting up early? Who chooses to get up early, but may not particularly enjoy it?
My take would be that we are dealing with a distinction that has more to do with semantics than syntax. Let us rewrite the first sentence of the above pair in two ways :
Gavin likes getting up early (in order) to enjoy the quite.
Gavin likes to get up early (in order) to enjoy the quiet.
Both these sentences are, to my mind, well-formed and describe the same attitude on the part of Gavin, i e, pleasure.
What about Pete ?
Pete likes to get up early (in order) to enjoy getting to work before the rush hour starts.
Pete likes getting up early (in order) to enjoy getting to work before the rush hour starts.
Max Weber would probably be disappointed in me, but I find both the above a bit odd, I think because I find it difficult to believe that this is a matter of positive pleasure (enjoy) for Pete. He surely likes avoiding the rush hour snarl, but that sort of negative pleasure doesn't seem - to me at least - to merit the description «enjoy». Therefore, I think BD's textbook is right in substance, but wrong as to the cause - it's simply easier for us (at least those of us who haven't really internalised the Protestant work ethic) to enjoy the quiet, rather than getting to work. (That being said, I usually enjoyed working late at night at the hospital, just because it was quieter, and I was reasonably assured of not being interrupted....)