Well, let’s be honest for a moment. The entire idea of having to pay for seat assignments is a huge money grab by the airlines that disproportionately impacts those flying with small children for whom sitting together is a “need to have” as opposed to a “nice to have.”
So this isn’t entirely about planning, but also about what can be material additional expenses.
Normally I would agree with you, but I think things are changing.
A huge pet peeve of mine is the inability to compare apples to apples. For example, on the Hilton Honors Website, it will show a list of hotels in the area, and the price per night. Sounds great, but in the Orlando area, some of those hotels have resort fees. They are mandatory fees (money grab), but not included in the listing. So, I choose the $102 a night hotel as it is cheaper than the $107 a night hotel, only to find out that the $102 night hotel has a $30 a night resort fee.
I recently flew Frontier Airlines to Orlando. How could I go wrong, I got a ticket for $20 one way, and $22 return. I bought two, one for me and my wife. Frontier is all about à la carte pricing. We did not need to check a bag, or bring a carry-on (for something like $40 each way), as our overnight clothes would fit in our one included personal bag.
In continuing my ticket purchase, I was then presented the option of choosing a seat. Every seat on the plane had a cost. In my circumstances it was $13/$25/$40. You could choose not to spend the money and have the airline assign you a seat, but since my wife and I wanted to sit together, I choose a pair of $13 seats each way.
That “$20 bill” ticket turned into $150 for two of us round trip, including seat assignments and taxes.
Now the kicker, as we are boarding, here is a woman complaining loudly that her and her daughter (I estimate to be in the 6 to 8 range) are seated 15 rows apart. My wife is looking at me and asking if we should offer to trade with them so they can sit together. Once on the jet way, I remind her that I paid extra money to make sure we would be seated together, and that she simply had actively chosen not to do the same. Now she is suffering with the outcome of her decision.
I hate to be so cold about it, and if I had not paid extra, I would have felt differently. To me, I felt that she was attempting to get for free an option that I had paid for. If the airline gives in, good for her.