It is still unclear why kill a business, that can bring much more dividends or can be sold for a lot of money.
To me it is like killing the goose that lays the golden eggs.
I'm not entirely sure why either. Historically when this pool was bigger, changes were always very hard to come by and it was very conservative in adopting them, which of course did actually add to its stability since everything worked - but they were the last to adopt change. Heck they didn't even have ntime-roll support for the longest time, relying on sheer brute force of generating unique work items for each miner based on the vast amount of server power they had thrown at it, which no one else could afford at the time. Once pools started to move to stratum, there was no sign this pool was going to join in, and then about 6 months after the first ASICs appeared and every serious remaining pool was using stratum, Tycho briefly asked a question about stratum implementation on the stratum thread which was the only sign he was interested, but it never eventuated. By that time this pool had become nigh on irrelevant and perhaps they assumed the stratum thing wouldn't be required, or that multi-TH machines wouldn't exist or whatever, but that proved wrong. Perhaps by that time the mega amounts of BTC they'd accumulated made the prospect of having to refashion the pool and maintain a whole new infrastructure proved uninteresting as a "job" for lesser rewards than they'd already made.
You'll note they skilfully address any actual issues with the pool, responding eventually to support queries, but continuing avoiding responding to any of these discussions or desperate pleas for modernising the pool. The smug way they responded to people almost demanding they upgrade or charge lower fees slowly stopped new members from joining and existing members were forced to move on. I originally watched that behaviour in amusement and never said anything, but it has been over a year since ASICs hit and the pattern has been steadfast. Perhaps more notable members of the community speaking up will make them respond... or not.
I might also add, a lot of the pool hashrate used to be coming from Russia and China and were probably "deals" which are irrelevant today.