Phillips Opto is low cost and low risk.
Turnkeys put the onus on the supplier to meet the often stringent part specification and process time requirement of the customer. Generally expensive, sophisticated machines are the basis for highly defined, inflexible processes. The customer’s environment is often a variable which is little known to suppliers, potentially causing expensive adaptions to the process. The process is generally fraught with risk which is priced into the turnkey. Often suppliers work to keep their know-how or trade secrets from the customer. The expectation that the supplier provide a fully functioning system that meets quality standards, process times, and delivery and installation schedules with little support from the customer and a secretive supplier tend to create an adversarial relationship between supplier and customer.
To sum it up turnkeys are expensive, risky, and tend to lead to unsatisfactory adversarial relationships.