If he wishes to ignore the current back up on bugs and optimizations and the possible large amount of clogged code, that is up to him to decide upon! However, the longer he leaves things as is the harder and harder its going to be further down the line to fix future bugs and optimizations.
Anyways, I am done with this thread. It was fun while it lasted
Dude, optimization is saved until near the very end of development, that's practically software design 101; optimizing prematurely makes it significantly harder to make further changes without screwing things up. In fact, according to the standard software release model, we're still in alpha, and bugs should only be fixed as necessary. This would be followed by a beta consisting of a feature freeze, bug-fixing, and optimization.
Granted, Dwarf Fortress's development is not something I'd call in any way standard, but ultimately, development is intended to have an endpoint.
Now, perhaps Toady should opt to go into beta now rather than later, focus on tightening up the existing system, optimize code that is not expected to change further, and make the interface more user friendly, then begin working towards Dwarf Fortress 2.0 with another wave of features; that's the general idea of what the OP is arguing, and while I don't necessarily agree with him or her, DF could use some polish.