Reine, while I would agree that there is a sexual aspect to this for many, I would guess your method of arriving at your conclusion to be flawed. I work in SEO and am very familiar with how google locates results based on searches ( by the way I found a non sex related result at the bottom of page three LOL).
Methodology for search engine optimization is based on many complicated formulas, but all the sites you find when searching "crossdresser sex" are porn sites which have a vested interest in placing high in search results and so are without doubt actively at work feeding info into their sites to do so. However, to assume that these results indicate the conclusion that most CD are sexually motivated would not be logical. My guess is that the majority of people seeking out these sites are otherwise heterosexual males (and females ...you might be surprised lol) seeking porn about CDS and TS rather than TG themselves. There are a LOT of seemingly "straight" guys out there secretly fascinated by TG women. A LOT. I could show you the messages I get every day on Facebook to prove it. And that without even mentioning the results of an experimental week I had with a profile posted on okcupid. Sheesh.
But again...the vast majority of these "hits" were from seemingly straight males and so I think it fair to assume the results of your search only prove there is a LOT of interest in porn about TG but do not prove anything about the number of sexually motivated TG.
But that is not to say they don't exist. Of course they do and most all of us know they do.
I had a great discussion wth a friend once about the perhaps conflicting narratives that motivate TG...one being identity driven and the other sex driven. I am not certain there is a strong dividing line between the two. Just as I feel there is a spectrum in human beings for gender rather than a binary (gender is not black and white), and just as I feel there is a similar spectrum for sexual orientation, I also feel there is a spectrum motivating gender expression that ranges from the sexually driven to the identity driven. And a spectrum on which individuals may start in one place and end in another. The narrative can and often does change, just as sexual orientation can also (and often does) shift with transition.
Complicating that spectrum is the play of testosterone and the age at which cis males transition. Often, by the time gender expression reaches a boiling point it occurs in a cis males life cycle when testosterone levels are high and motivate an equally high libido. There can be and often is a confusion that occurs between the relief of dysphoria that expression of identity brings and the euphoria that arises from that relief, versus the sexual arousal that sometimes accompanies euphoria. They are not the same thing but it may not be easy for an individual to mentally separate the two. Not, at least, until the passage of time and a growing familiarity with "dressing" remove aspects of that initial relief driven euphoria replacing them with calmness and a growing realization of identity as being the primary motivator.
What I'm saying is that the statement "There are tons of men who wear items of women's clothing for just sexual thrills and no other reason" is in many ways a gross and unfair oversimplification of the subject.
Carl Sagan once observed that the human brain is the single most complicated object in the known universe. He was right and we are a long way from understanding how it works. H.L. Mencken once observed that "...for every complicated problem there is a simple answer...and it's wrong". He was right, too... don't you think?
Oh, and BTW, I kind of think that there is also some confusion among many about gender and sexuality. Ones gender expression may be fully driven by identity without that precluding a healthy interest in sexuality. I sometimes feel as though to be accepted on this site, TG must somehow prove themselves almost asexual in order to "prove" they are pure and motivated only by identity and not sexuality. It is entirely possible and quite healthy for the "purest" identity driven TG to still maintain and desire a natural sex life... isn't it?
