> which are temporary work visas; but easy to get

I wouldn't say that the L1 visas are easier to get. The only material differences I've noticed between L1 and H1B visas are

* the first is not lottery based,

* you must have worked for the company in another country for at least a year (time spent in the US while working for the company doesn't count),

* that an L2 holding spouse can have an Employment Authorization Document pretty quickly (instead of H2B visa holders, who can only apply for an EAD fairly late in the process after being in the country for years),

* L1 visa holders cannot change jobs, while H1B visa holders can (as difficult as that process can be).