More of a general gardening problem/question than a Growing from Seed forum question so I'd suggest posting on maybe the Vegetable gardening forum for more input.

The things that come to mind is the holes getting plugged with dirt/mud/small gravel or sand depending on what is in your soil You'd have no way to know it until plants in an area started wilting. Then you have to dig up the whole garden to fix it.

Plus it would limit your planting depth and layout and would be easy to damage with planting tools.

You can accomplish, and many do, the same thing by just burying the soaker hose itself. That way if one place gets plugged there is still ample way for the water to get out. But even then you have the basic problem to overcome of gravity - water difusses down - below the roots.

You can switch to a drip irrigation system on top of the soil and accomplish your goals without all the problems.

Dave

I would go with something like this:

Here is a link that might be useful: Running water to raised beds