I am going to distinguish between going public to list the shares e.g. FTG vs an IPO that sells shares to raise capital. I am referring to an IPO.
1) Cost of going public. Ads on TV, radio, newspapers. I think some of this may be to follow CMA regulations. These do not come cheap.
2) AGMs, EGMs, etc cost a lot of money. Perhaps cheaper now with virtual AGMs.
3) Maintaining a shareholder register. Paying Image/C&R. Some shareholders have shares worth 1,000/- but cost 1,000/year to maintain!
4) Slow pace of concluding deals given the need for EGMs, etc that create publicity and take time. Look at the Kantar sale by WPP Scangroup which almost got derailed since an EGM was needed.
5) Unless the capital raised is cheaper in a listing vs PE, why go that route?
6) Easier to exit when private vs listed. Less drama.
Greedy when others are fearful. Very fearful when others are greedy - to paraphrase Warren Buffett