The phrase "should not be solely" is correct and can be used in written English.
It is typically used to express that something should not be the only factor or source of information. Example: "When conducting research, online sources should not be solely relied upon. It is important to also consult reputable books and articles."
Morrissey adds that while she wants the service to be as successful as possible, the industry should not be solely dependent on a single platform.
Leiter spent 10 minutes last week explaining how the Mets should not be solely concerned with the Braves because the rest of the division has improved.
In most modern two-parent families in the United States, arranging child care is not, or should not be, solely the responsibility of the working mother.
Mr. Barak also challenged recent accounts of last year's Camp David negotiations, which say that the blame for their failure should not be solely on Mr. Arafat.
The focus should not be solely on the access to education, but also on the relevance and quality of education, and its link to skill formation.
One official from the lecturers' union, UCU, says the future should not be solely about "basic stuff", but should embrace the educated minority in jail for "white-collar" crimes.
Ultimately, it shouldn't be solely up to the partner whose body bears the brunt of contraception to inform the one whose body isn't about how it works or how they can help with it.
Regulators shouldn't be solely concerned with whether a pesticide is hazardous in the lab.
Hormone replacement therapy is only indicated in the US for the prevention of osteoporosis and should not be used solely for this purpose.
The decision should not be based solely on the advice of hospital doctors.
The World Trade Center site should not be used solely as a site for a monument?
