There are worse companies to get bought by, but if you've only ever worked at startups then you're not likely to enjoy what this becomes.
When IBM acquired that company, after a few weeks, this guy had a meeting with new engineering people. The very first meeting, they changed things for him. Instead of a single winding road of development, they wrote out a large spreadsheet. The rows were the distinguishable parts of his large'ish and clever architecture; the columns were assignments. They essentially dismantled his world into parts, for a team to implement. He was distraught. He didn't think like that. They did not discuss it, it was the marching orders. He quit shortly afterwards, which might have been optimal for IBM.
One could argue that to deliver his best continuously he adapted to changing circumstances and left.