See http://blog.macsales.com/21641... for an example of a properly designed SSD.
kext signing is a GoodThing for security. Making the system less secure so that lazy implementors are protected isn't a good trade off.
Apple *should* have provided a better upgrade experience so that users wouldn't be surprised, or end up with unbootable systems. Users that don't want to have kext protection CAN turn it off see http://www.cindori.org/trim-en...
To me this is akin to Apple's desupport of WPS ages ago. It took everyone else a while to figure out that WPS was a major security hole (indeed, its still there for most consumers).