Because they know that you will be super flattered by their manly attention and they know once you see them, you will fall over with sheer delight at the sight of their masculine beauty, and then you will bow in awe.
You should be grateful FGS. Cheer up luv it may never happen. 😂😂😂
Seriously, I am so glad I live semi-rural, and can run along the canal path, or the river bank. (Or around one of the country lanes that aren't too far from me.)
Meglet, you are incredibly fortunate if you have never suffered cat-calling whilst out in public. I have known many (usually) young women who have had to give up running outside, because of constant harassment from men.
Do men not get at all how it makes women feel? It's horrible. All they are doing is trying to impress their mates by acting all 'blokey.' On what planet do they believe women enjoy this letching and cat-calling? 
I would probably leave my DH if I thought he was behaving like this towards women on a regular basis; cat-calling and letching, and suchlike. I'm not kidding. Yet many of these men (probably) have wives or girlfriends.