Eh, I get it but the difference with Walker is there is plenty of tape of him wrecking games off the edge. I don't ever recall seeing Isaiah Simmons do that at safety or linebacker in college.
Personally, I never got the hype with Simmons. There aren't many examples of college hybrid linebacker/safeties going to the NFL and excelling as hybrid players, but there are a number of guys who have made the transition from LB to EDGE. Micah Parsons is the most obvious current day player, but Von Miller did this as well. Khalil Mack did to a lesser extent, too.