'Widely' is a very subjective term. Most people I've heard of that watched it when it was on TV, and a few years afterward on DVD, loved it. But also most people I've talked to that heard about how great it is and tried watching it over the last few years, didn't like it as much.
The Wire ran for 5 seasons in the early 2000s, right? I'm estimating it was GREAT for its time, but watching it now comparing it to modern TV shows.... its lost its luster.
I guess I can compare it to my favorite videogames of that era. They're still awesome in my perspective, but if I doubt a modern teenage gamer would appreciate PS2 or original X-Box games.