I can't say I've read anywhere near enough about the profiling issue to make anything like an informed judgment about it, so I won't (it's a rare talent I feel these days to be able to say 'I don't know').
Regarding the ideological purity: I see it as being unwavering in your pursuit of a mythical Party that is both electable and also matching you exactly in your ideology. Corbyn, for his many issues, had a wealth of policies that I'm 100% on board with, but I acknowledge that Labour under him, lost two elections to two of the worst PMs in our history, giving one an absolutely horrific 80-seat majority. Because of that I've acknowledged that I can't realistically find a party that is likely to be elected, that is anywhere near to my personal political ideology. Therefore, I look at which of the electable parties is closer to my desired destination.
I've posted before about political parties being busses, not taxis. They won't get you exactly where you want to go, but you take the one that gets you closest. Starmer may lie about being able to take me to the proverbial end of my street, but he's heading in the right direction, so I'm going with him.
Ideological purity is the equivalent of staying on the bus that's heading in the opposite direction, all the while complaining about the direction the bus is going, all because the Labour bus didn't have a stop outside your door.