Onions and shallots- why leave tip sticking out when planting?

Just been planting onions and shallots. As per instructions, I left the tips pointing out. As usual and despite netting, birds have been merrily digging up and scattering them. When i planted garlic back in November, I didn't leave anything sticking out. The growth is now strong and vigorous.
The onions I planted in November on the other hand are weedy. There is some distortion of the leaves where they bumped into the netting.
Why not just plant onions and shallots by starting them off fully underground? Has anyone tried this?

Actually, as per my grandfather, I always do fully cover them.

I fully cover them as well and yes, they do seem to work their way back up again. The bulbs are on the surface for harvesting, where you would expect them, but the birds leave them alone when newly planted 

The crop seems unaffected.  I only just cover them and pinch off any papery bits so they are not planted deeply at all.

We have lots of birds on our site and if you plant with the tip showing, out they all come and you end up replanting on your next visit.  Now that does somewhat knacker your chances of decent onions.  They really don't like the hokey cokey treatment

I plant them with the tops showing but then draw some soil over them to make a low ridge so that they are covered. When you hoe later the soil falls away.

Even with netting over them onions and shallots are sometimes still pulled out and scattered. I have always assumed that this is mice.

That's interesting I do mine like DD and New Shoot.  I fully cover them.  I started doing it because of the birds and I don't like using netting if I can help it as it has caught some birds in the past and we have a lot of cats on our plot.

Overall the crop yield is as good.  I reckon I probably get a few more thick neck onions which I process and store in the freezer

Thanks everyone for your input. I have planted a few shallots under soil and will see how they go, the others were planted conventionally. it'll be interesting to compare!

Unless I pre-sprout them in modules I bury them slightly on the basis that as the soil settles after a few rain storms they en up at the surface, by then they should have rooted and shooted so won't get pulled up.