There are those of us who are security minded and will in fact download the script and check the sha1/sha256 and review the script before running it. Any time I see this curl sudo thing is when there's always another (manual) option. The shell scripts themselves aren't so complex that you can't figure out what they're doing, they're normally fairly straightforward, unless they were generated by some tool, or are in fact malware, so you can see if something looks funky before you run it. Sure, there can be a malware that makes it so you can't tell, but normally not.