I doubt they had a higher offer. If so and they didn't take it they'd be open to real legal action, not just these trolling law firms that appear with every merger. I'm disappointed that NICK didn't command a higher price. I bet most stockholders are disappointed.
I bet the background is in the SEC filing by now. So it might say if there were others interested.
Ive seen a number of deals where the highest bidder didnt win because of uncertainty but usually, or often, the buyer ends up matching the other offer.
In other words, the board might say that $15.75 is better than $16 from a buyer who might not get financing.
Im ok with the deal because it allows me to keep my low cost basis & avoid paying taxes for many years.
Of course, I ended up getting killed on a deal where I held the new companies stock and they later had big problems. I owned SUAI which was bought out by TWGP. I should have sold the stock & not taken the new companies stock & held it.