The phrase "nasty habit" refers to a behavior that is not very nice or pleasant. It suggests that the person or thing has a regular tendency to do something that is not well-liked or considered inappropriate. Full definition
Now that you've all recovered, it's that time of year where we make a list of resolutions of what we plan to accomplish or what nasty habit we want to break. (crackberry.com)
In fact, they've a rather nasty habit of going ex-growth without warning, while simultaneously shitting all over you with a bunch of loan write - offs. (wexboy.wordpress.com)
In hindsight, the release of the SG - 1000 and its add - ons / second iteration now seem like the beginning of one of Sega's nastiest habits in the 90s: selling untested experiments rather than fully finished products; see also 32X, Sega CD, Saturn, etc.. (segadoes.com)