*A marginal number of the pirated games really represent a loss and it actually can bring profit by turning you into a fan of a franchise of the game you pirated out of curiosity/lack of money.
(There are plenty of studies that shows that pirates are the biggest spenders/consumers of legitimate media)
*Piracy was the least of the problems the Dreamcast had, SEGA's lack of money, the console being sold at loss, the cost of Shenmue's development and most important the hype behind Sony after the original Playstation were the real reason it failed.
*PSX, PS2, NDS, Wii/X360 were the most easily pirateable systems of there generations and also the most successful.
-The PSX and PS2 would not read without a modchip of some sort (or the slidecard for the PS2 if you wanted to go that route). Dreamcast could be pirated using things so many kids had available at the time: a computer, CD burner, a Dreamcast game borrowed from a friend or rented from a video store, and a quick online tutorial. Even the later generations that had anti-piracy measures were worked around without the use of a modchip.
-The NDS was hurt by piracy but because children occupy so much of its market, piracy wasn't that big of a thing. Not that many 40 year old parents are going to go trolling rom sites for their kid, or buying flash cards from websites that they don't recognize.
-The Wii has the homebrew channel, but piracy on it isn't perfect because of the continuous updates and difficulty of getting the ISOs onto the device. Fitting them on a 2GB card isn't always optimal, and not everyone has a portable USB hard drive lying around.
-The 360 has some of the same issues as the PSX/PS2 in that you have to modify the system (albeit through software at this point I assume) to allow it to play modded games.
Aaaand of course the existence of the DMCA that wasn't even an issue when the Dreamcast was out makes things sketchy, because there is now a risk of being caught.
So no, the Dreamcast was not harder to pirate than these other systems; I would venture to say it was the easiest requiring no additional hardware or changes to the unit itself. Not quite as easy as copying floppy disk games like we all did in the 80's, but still pretty simple. Like I said in my post, piracy was only one reason the Dreamcast failed--but it also had some good things going for it that could have saved it if game sales were successful.