On the hemline and also some styles will have in on the sleeves (short).

The controversy MIGHT relate how one's body is built. With an elastic, it might not matter for certain figures or for others it might accentuate certain things you might not want..ie. meno-belly, etc. Someone who is tall, long waisted might also have additional comments on elastic thing since I'm pretty short and hence, length + elastic is not a big issue.

No elastic is fine too and more desirably, if jersey design has also A-line side panels to flatter a bit instead of too boxy straight lines at sides.

Personally, I prefer no elastic and I'm slim. It's just me. That includes no elastics at the sleeves.