It's not gatekeeping.
Traditional engineering fields have somewhat standardized expectations around what a new grad should know. Same as law or Medicine/Nursing. When someone calls himself a Software Engineer, I too have an expectation of what they should know.
It's part of what made the scene where Katherine Johnson explains Euler's method as a little known math trick to a group of bewildered NASA engineers so funny. Everyone in that room would have been familiar with that concept as it's the first numerical method encountered in a differential equation class [0].
I would love some sort of standardized curriculum for Software Engineering. No exam, just a list of pre-requisite and concepts.
[0] The real work she did would have probably required a separate two hour documentary so I understand the filmmaker's decision here.
Profilers are simple tools that every software engineer should be familiar with. They are literally just a way to measure performance of a software system. The basic ones do this by tracking time, or counting the number of times a block of code are entered. People have recreated them a million times (probably more) because they're so damned easy to create.
I'll take my hit for this one: If someone were to come up to me and say, "I'm an engineer, but I don't know how to measure the software I make." I'd think they were a hack, yes. If they instead were honest and said, "I'm a student studying to become an engineer ..." or "I'm a novice trying to become better..." then at least they're honest individuals and not liars or hacks. If that's gatekeeping, then so be it. They are not engineers yet if they can't use the software equivalent of a ruler.