Well, why would anyone bother being an Old Earth Creationist? The only reason for being a creationist is to defend the literal truth of the Bible. Anyone who's prepared to admit that the Genesis story isn't literally true might as well go the whole hog and admit the fact of common descent as well.
Because the Bible's literal truth is open to interpretation. One way is to assume a big gap between the first and second verse of the Bible:
Gen 1:1 - "In the beginning God created the heaven and the earth."
And then thousands of millions of years, followed by the earth that was 'void and without form' in the next verse - possibly because God wiped it all out to try again.
Another route is to claim that the 'days' in Genesis are being used in a poetic sense to simply mean 'period of time'; and that the creation week might well have taken millions of years.
A third option is to pick the point in Genesis where it appears two creation stories have been stuck together. Once Creation week is over and everything's been created, God then proceeds to do it all over again from Genesis 2:4 onwards. One literalist interpretation is that, once again, God wiped everything clean and started from scratch. The earth then, can be ancient and the fossils real examples of animals that lived millions of years ago, but they were all eliminated before the most recent creation of life a few thousand years ago. One interesting spinoff from this idea is the adoption (via Jewish mysticism) of the old Mesopotamian daemon Lilith into Christian folklore as the woman created in Genesis 1.
Reading something 'literally' doesn't necessarily mean any agreement on what's actually being said.
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As to the main question, isn't ICANT an old-earth, old-life creationist?