I'm not sure if I should laugh or cry at that question. I know most people don't realize this but the iPod Touch (although it has 16GB of storage) only has 120MB or so of RAM. Think back to those halcyon days of yore when you ran a full operating system (like XP) and web browser using only 128MB of RAM. Remember how many crashes you had? And how many times you had to quit and restart your browser because it bogged down because you were out of memory? Ah the memories... brings a tear to my eye... And don't forget that web pages nowadays are a LOT more detailed (using CSS, Javascript, etc.) than the pages that we used to surf on those 128MB platforms.
Oh, and I wouldn't consider it a "defect" with regards to opening a new page - it's a limitation of the memory that's available. I doubt it will be fixed until Apple ups the internal RAM which won't be just a firmware fix.
Safari on the Mac is a good, solid browser. I've really no complaints with it crashing or being unresponsive. Now in terms of full disclosure, I'm definitely looking to Firefox 3 (currently beta) on my Mac, but not because of performance/crashes. I'm looking at Firefox because Foxmarks lets me sync bookmarks between Firefox on all three of my platforms (Windows XP, Ubuntu and Mac).