RAT 5
How can ATC impose visual approach criteria? It would suggest they are radar vectoring for a difficult energy management visual approach.
Been a long time since I managed ATC facilities, so my terminology may be a bit imprecise.
ATC is responsible for managing the safe, orderly and expeditious flow of air traffic through a given block of airspace, with specific horizontal and vertical separation requirements. ATC effectively routes you to a given point in space at which the approach is now the pilot's task, be that intercepting a precision instrumented approach fix, a non precision instrumented approach fix, or a visual approach fix. For an instrument approach fix, obviously, you should be at an altitude and speed conducive to flying on your instruments according to the published approach, as the instruments are your only reference until you can take over visually. Since the approach profile has to be able to deliver you, without any visual reference, to DH or MDA in a stable configuration, airspeed and altitude at the point of initiation of the approach is important, so that you have proper control of the aircraft when "breaking out".
The whole concept of a clearance for a visual approach is that you have visual cues to make the approach from the time your are released at the visual approach fix through to touchdown. It is pilot basic skill that is called upon to manage the approach, not instruments. At the risk of sounding impudent, that's why it's called a "visual approach", not an "instrument approach". And yes, for separation and airspace management reasons, you may be expected to work a bit harder on a "visual approach", but it is an approach from which you have visual reference for a considerably greater amount of time and space to execute the maneuver to the touchdown point.
Yes, it's much easier to shoot an approach in VMC using IMC intended automation. But, since, allegedly, all aircrews are capable of flying an aircraft visually, when an airport is VMC and the safe, orderly and expeditious flow of traffic requires the pilots to use these alleged skills, it is, at least to anyone who has managed airspace (not just operate a single aircraft in airspace) reasonable to expect crews to expend the extra effort they are alleged to be certified to possess. Knowing, however, that some pilots may not be as skilled as others, ATC entertains requests for special handling. Keep in mind the phraseology is "cleared", not "ordered" to make a given approach.
If the regularly issued ATC clearances are over taxing aircrews, then the aircrews should report them as such, no less respond, "Unable". The silence of the pilots is their implicit assent to such approach conditions. If you are waiting for the NTSB to investigate a mishap that proves your position that a given approach, about which the pilots remain formally silent, is over taxing, then your failure to come up on the frequency before the fact could quite well be a contributing factor to any mishap that such an ATC procedure may, at least in your eyes, cause.