In reality, that statement is nothing more than his personal opinion.
Literal
Actually that statement [topic-は] his personal opinion [limit-にすぎない].
~にすぎない ('nothing more than, merely') downgrades the importance of what precedes it. 個人的見解 ('personal opinion') is a formal compound — 個人的 ('personal') + 見解 ('opinion/view'). The sentence has a rebuttal tone.