Because US loves other songs) Maybe)

Plus they never really toured in the States to any great extent.

I remember around the time "This is Hardcore" was released, someone ran a poll on their website entitled "What do Pulp have to do to make it big in the US?", the options were something along the lines of:
Release "Glory Days" as a single
Write a song like "Song 2"
Don't bother, US' tastes suck
amongst others

Anyone remember it? I can remember which one had the most votes...

Anyway, if you want my opinion, I agree with Eamonn and Sturdy. It's a shame really because I've got a few bootlegs of US shows and they're pretty good, especially the Boston on they did on the first night of their 1998 tour.

maybe the US appreciate his solo work more

Yeah, they were an awkward bunch, not cut-out for heavy touring .They probably all wanted to kill each other when the curtain came down on Different Class at the end of the summer of '96. Candida certainly hated it, Russell had a family at home etc. It's not like they were a young wide-eyed band who a record company could pack off to America until they had made some money.

Spending their formative years scrapping round for gigs at any place that would have them, chipping in with petrol money to go down to London mid-week in a clapped out transit van playing to a couple of dozen people if lucky...good craic at the time maybe but enough to remove any glamorous facade that long-distance touring may have.

What Sturdy said.

Its not easy to break a band in the US, or at least, to break into the 'mainstream'. You really have to have the full support of your label, the record and radio industries... and that requires a lot of greasy palms.

Britpop in general didn't fare that well in the US. Blur never really broke into the US mainstream either, aside from Song 2, which owed most of its popularity to an Intel Pentium Processor advert. Oasis broke through because they seemed more familiar and more 'classic rock'. Of the core Camden Britpop scene, Elastica was probably the most successful, and that's almost entirely due to their sex appeal (and good, short songs).

The Britpop bands also seemed a bit snide and dismissive toward Americans in their interviews. Here's a hint: if you are invited to a friend's house for dinner, and you spend the whole time complaining about the food and the table settings, you probably won't be invited back. The handful of british acts that broke through to the US market in the 00's (Franz Ferdinand, Travis, Coldplay, etc) learned the lesson and were excessively polite.

Anyway, the US pop music marketplace has long been dominated by 'urban' (re: black) music. By the time This is Hardcore was released, there really wasn't much room on US commercial radio for new rock/ indie/ guitar-pop whatchamacallit.

One of the questions you might ask yourself is: why were Pulp successful in the UK? Some factors: years of touring and playing local dives, hometown heroes, Jarvis was a minor celebrity, Pulp and Britpop enjoyed support from the BBC and its mandate to promote new British music... none of these factors mean anything to the US record buying public.