is it so they lead a ladies eye to the parts they would most be interested in ?
…maybe.
Not all of them are pointed. As a matter of fact, I think most are not pointed.
ties were made to cover buttons.
Yes. That also explains why ties were really thin in the 80’s. Because in the 80’s, men had considerably smaller penii than in these days.
Now, to the actual answer. The shape of the tie is determined by fashion. The origin of the tie is not to cover buttons, as handy states. Neckties were first worn by Croatian soldiers. The purpose of the tie was to wipe sweat from the forehead, amongst other things.
The French called the tie “à la Croate” (Croation style), which soon was bastardised to the more familiar cravate.
It’s so everyone will know where their brain is. 
I remember years ago a time when ties were straight along the bottom instead of pointed. Then there was another time when they were real wide. I think Barthes the famous poststructuralist or structuralist philosopher said that certain trends in fashion go together. For example when women’s skirts go up something changes on the blouse, I don’t remember what, like the width, and when their skirts go down that same feature on the blouse changes, but it isn’t a matter of both features become more revealing in one period or less in another. There’s just this meaningless connection. Also, I heard that ties were a pha—c symbol meaning not to point to anything but to show that anybody who would actually wear one was willing to strangle his natural self with this rag and behave in the business world.
And if the cravat was a dewrag in origin, then how to explain the bow tie?
Because they’re happy to see you. 