Architecture – Static Methods in Business Layer to achieve data from DAL! Yes? No

Some advice here,

I've run into a system where the DAL contents of hundreds of sql command calls are split up on a class per table. There are also a Business layer which get it's data from this DAL, recieving it further to other methods and layers in other places.

Nearly 100% of those Business Methods are pure forwarding of data. Few of them contain logic that affect the data (because the data are already sorted/evaluated or somewhat in the sql-commands/stored-procedures.

Now to the real question.
All of those methods in business layer are static.
This is easy because I can call them from everywhere without instantiation.

Is static methods really preferrable?
Why and how do you think?

I mean static methods need to be in heap and so far I really can't se the cosmetic profit because of it. I also feel the whole system is very hard to debug, especially now because the system has V E R Y high variety of response time, without many changes in load from users.