The area around Euston may be boring but it's not in any way rough other than on the Platform 1 side where "a bit seedy" is about as far as I'd go. It's got nothing on what the area around Kings Cross used to be like, or the back streets around Waterloo.
I remember King's Cross in the late 80s/early 90s... the walk to Thameslink was an 'experience', with run-down shops, 'ladies' hanging abut and the telephone boxes full of cards! Nowadays it's much more upmarket, with coffee shops etc - even the strip bar, the Flying Scotsman, has been replaced by the Scottish Stores which I've had a decent pint or two in (and at a better price than the Parcel Yard).
With regard to Waterloo, there seems to be a lot of redevelopment going on in the Lower Marsh area at the moment, with hotels popping up. I see from
http://www.london-se1.co.uk/news/view/9142 that Steve's B&B, with its kebab house below is being replaced by a boutique hotel which will presumably be aimed at the higher quality end, and assume the "very welcome removal of a negative contributor to the street" mentioned at
http://www.london-se1.co.uk/news/view/9166 is referring to the Chariots Sauna that closed this month.
Going back on topic there seems to be mixed views on the Bree Louise, but I liked it - partly as I could get a decent meal (pie, mash and veg) for £6 (£2 off with a CAMRA card). Fortunately, there are a good few other places to go in the Euston area.