Yes I think that Lady R (While she MIGHT feel obliged to make herself beleive that Sir W wasn't a bad landlord.. since she's a bit prejudiced on the side of ancestry) is in THIS instance referring to his being her own landlord and being problaby obliging enough to suit her..

However he may not be THAT bad as landlords go. If he has a good agent, he may be willing ot let him do what is needful and not interfere too much so long as he gets his rents.. and fi the agent is willing to work hard and is able to persuade his boss that it will bring in more money if he treats his tenants well and does thier repairs and puts money inot the land, SIr W may allow him to do the job properly. He may indeed think it is beneaht him to be niggling and cheap, or to bohter much about running the estate... so in that sense teh tenants are not badly treated...
And probably until his debts began to soar, he was reasonably generious wiht his charity to the poor...