Okay, I'll bite. Here are some cons. I had a pool for 19 years. Sold our house about two years ago and haven't missed the pool yet. I live just north of Boston and we would open the pool usually by Memorial day and didn't get much of use of it after Labor day....so about 3 months of use per year.
First, there's the costs involved, not just the initial cost, but the chemicals and other supplies. I used mostly chlorine and baking soda (to clear up the water after rain) would resort to other chemical only when we had a problem. In those 19 years we had to replace the liner twice (they last about 10 years) the filter once, and the solar cover numerous times (had the same reel though and that's what costs more) Also, we ran the filter for about 8 hours per day, during the day so your electricity bill will be higher. Then there are the hidden costs..the cost of the extra soda, freeze pops and chips you have to have around for when your guests are hungry and thirsty
Then there's the time. You spend about a day opening it in the spring and closing it in the fall, unless you do it yourself and then this would be in the paragraph above. You have to vacumm it. Every year was different from an algea standpoint. Some years were no problem, some years I couldn't stay ahead of it. I did resort to the an automatic one, but that only did about 85% of the total surface. There always seemed to be the most algae when I knew someone was coming over. Try telling your kids to wait for a half hour while you vacumm the pool.
Then there are the rules. You make them, you enforce them. No running, no rough housing, whatever..it's your pool and you're the one liable. You'd be surprised how many people don't watch out for their kids around pools and are concerned with enforcing your rules.
You do end up with quite a collection of beach towels over the years. HTH