Why HMS Furious kept an obstructed flight deck

Why did HMS Furious retain bridge and funnel obstructions when a flight deck was added?

The existing structure and urgency of conversion mattered, and designers had not yet realized that a full-length unobstructed flight deck was necessary.

Furious retained much of her superstructure because it had already been built and the Royal Navy wanted the ship in service quickly. Designers had not yet learned that a full-length unobstructed flight deck was essential. The conversion records carrier design being worked out through use. Its awkward deck was the result of urgency and incomplete knowledge rather than a belief that the obstructions were ideal.