Again this is due to people not understanding the concept and size of warships. The average heavy warship has a percentage of only 2% of it's volume in armor and hull, for that matter the average ship of any kind has only 1-1.5%. The Nimitz class ship if completely compressed into a block would be only about 30 meters to a side, including all the aircraft and personnel. By heavy warship, I mean battleships with 10+ inches of armor belt.
This is due to power restrictions more than anything else. To armour a ship to the specs your books specify would mean they'd need engines powerful enough to move a small moon out of orbit. You also need room for that massive crew.
The same thing happened in reverse when David Weber created his Honor Harrington series. About the time of book eight someone mentioned to the author that his ships were as solid as smoke in comparison to their size and mass. He was working with the largest ship being only 9.5 megatons.
As for weapons, you are correct that a hand weapon will not affect a warship, but saying a hand weapon will not affect a speeder is spurious. The golden BB theory was created by the Russian Army during WWII to deal with strafing attacks. It didn't work well, but it did work. As for smaller warships, you have to remember that the torpedo boat and destroyer were designed with the idea of getting close enough to use torpedoes.