Well, first I don't paddle in the ocean. Most of my paddling is on the Columbia River. Yes, the Columbia can get very rough at times, but I don't have to get half submerged to enjoy kayaking. Second, I don't think there are any rules that say a sea kayak can only be paddled in salt water, or very large lakes that might qualify as a sea.
I have to admit that I did put my skirt on yesterday when it looked like it was going to rain. The wind came up and the water did get a little rough, but I still would have been fine without the skirt.
If you are surprised that I rarely use a skirt, it will probably shock you that I have never rolled any of my kayaks and I don't intend to--at least not on purpose. My moto is that if I want to go swimming, I'll go swimming. When I go paddling, my intention is to keep the boat upright and stay dry. In all the hundreds of hours and miles I have paddled, I have only been dumped about three times and one of those was in a canoe; one was in white water and one was in my rec. kayak while surfing on a tug boat wave. A skirt, or the ability to roll would have done no good in any of those cases.
I am 65 years old and have learned to be prudent with my paddling and while I know that things do happen sometimes when you least expect it, I have great faith in my kayaks to keep me right side up.
Of all the kayakers I know, there is only one who has learned to roll his kayak. I admire his ability and his desire to go where he will surely need that skill, but it's not for me.