I have trouble understanding why a buyer would waste time and money negotiating the acquisition of a liquidating business if the only valuable portion of the company is 2 engineers. That's what recruiters are for.
1. There's real value to calling it an acquisition, to both the buyer and seller, though mostly to the founding team who can now claim they were "acquired" which is better than saying "I got shut down and got a new job somewhat related to the company I started." Buyer can also tout themselves as "consolidators" within an industry.
2. Usually, deals like this no more than $100K in additional cash will get pushed to founders and/or key employees each, which seems like a lot but assuming the founders and key employees are deemed REALLY good engineers, paying a recruiter for them could be upwards of $20K each, and if you treat the rest as a bonus it's not more than say, how much a 3rd year investment banker gets as a bonus, so it's expensive but not outrageous.
3. Investors want to say they have an "exit." The really confounding thing is why the investors would or should get any $$, though they often do. I understand the reasons (founders want to treat them well, the VCs may threaten a lawsuit if they are not), but it still seems pretty weird and unnecessary. I think it mostly has to do with companies having too much $$ and stock valued too highly =)
Because they invested in the company and company was purchased? I don't understand why you'd think for a moment that investors wouldn't get any money from the sale of an asset they helped created.
That said they wouldn't care about anyone other than the 2 engineers and any designers on board.