Even if an M&A deal could appear accretive, the synergies projected in the model could be too speculative, or there could be too much volatility or risk to the business.
There may be other strategic risks that won’t be captured by an Excel model. For example, there could be the risk of reputational damage if the target doesn’t have a similar credibility or brand as the acquiror.
Key executive members may move or become disgruntled if they feel the scope of their responsibility has changed, or they may be simply unhappy with the new culture and team.
Integrating the two companies’ operations may take much longer and be much more expensive than expected.
Also, the target may be too fundamentally different from the acquiror and be outside of management’s expertise to run effectively.