T2 security at FRA does take longer to pass through than T1, there is also a double layer for certain destinations. Generally, I avoid T2.
I pass through FRA a lot, it's my main airport and I have to say that I've found the security staff to be professional, polite and thorough. I've never witnessed any of them be less than polite, let alone unreasonable or abusive.
To compare FRA, in a bad light, to LHR is laughable. FRA is a reasonably efficient airport. LHR is not.