I've noticed this as well.
In fact, the idea that motorcyclist are being inconsiderate, selfish, lazy, whatever....simply disappears when the parking spaces for cars are limited. Sure....they all think you're a jerk if you park in the hashed area when there are 100 open spaces in the lot, but if there are limited spaces and you take one when the hashed area was open, just watch and see how inconsiderate they think you are then.
Case and point....last year at Banff (Lake Louise) and at Glacier NP at the lodge at the top, the parking lots were full and they were turning cars away and / or they were lined up for miles to get in. If I had taken a full space with my motorcycle, I'd probably have gotten into a fight with someone in a car that was desperate for a place to park. They were all more than happy to have me park in the hashed area at the end of the parking lot with 20-50 other bikes and not have us taking up 20-50 spaces that were in short supply.
This thread comes up from time to time and I always see the polarized answers but I'm really not sure why people see parking in the hashes as right or wrong. To me, it's completely situational. If you park between two handicap spaces in a wide open parking lot because you don't want to walk 100 extra feet, then yeah...your a jerk and inconsiderate. If you park in the end of a row that is hashed off at the mall and not by any handicapped spaces but only hashed off because they couldn't make full spaces out of it on black Friday where the cars are lined up looking for a parking space, you'll have 10 people that thank you for not taking a space. Use a little common sense and think about others...it goes a really long way into letting you know what the right thing to do is.