it is normal for them to affect 500 miles of coastline and not unusual to be a 1000 miles wide. In fact hurricanes are generally quite localized by comparison. For example all of Oregon and northern California can be hit by the width of a storm. I think the difference is the terrain. On the east coast the water is very shallow and the land very low. Hard to tell the difference between them at times. Very different from the west coast which is generally mountainous in the extreme by east coast standards. What you call a mountain on the sea we call a small hill. Cadillac on MDI is the tallest on the eastern seaboard at 1500 ft, would't even have a name out west. There are hundreds of peaks taller than Mt Washington within 50 miles of the west coast. That contains damage from waves and wind to a great degree. The depth of the water seems to prevent the sort of storm surge that you see out east. In many places you don't need to go more than a few miles out to be off soundings.

With regard to boats, on the west coast nearly everything is in a marina, nearly all marinas are actually protected by breakwaters and such, even when on well protected bays such as San Francisco. In the east, many mooring fields are really nearly open roadsteads, many marinas are open to the fetch of the bay they are on if not the ocean. I left my boat in the marina off of San Francisco bay in many storms with 50 or 60 knot winds without much worry.

I am a West Coast boy experiencing east coast weather for only the last three seasons - I'll take the west coast hands down!