For those of you here who are (obviously ) no pilots or controllers and jumping to conclusions , always good to recalls the facts and what the book says :
a) different frequencies for parallel runways is the rule and the norm in busy airports, can be combined when traffic decreases ( e.g night) .
b) approaches for runways separated by less that 2500ft ( as it the case here ) should be staggered and not side by side . The USA has filed a difference on that one . They are the only ones as far as I know. (waiting to be corrected)
c) Class D airspace does not include ATC providing separation between VFRs or IFR/VFR.
d) passing traffic information on other traffic is usual and was done here.
Then on using aircraft equipped with the GARMIN1000 screen in VFR ( as was the case here) , I flew with students in a few of those including the SR22s, far too much time watching the screens and not outside , and with ADS-B now, replying " in sight" is sometimes seeing it in on the screen and not visually acquired out of the window. .I am not saying this is what happened here, just an observation , and indeed the speed they had on base was not helping. ..